TABLE 4 ESTIMATES OF 13-MONTH SMOOTH SOLAR ACTIVITY FOR BALANCE OF CYCLE 24 AND CYCLE 25 TIME SUNSPOT NUMBERS GEOMAGNETIC INDEX (Ap) PERCENTILE PERCENTILE 95.0% 50% 5.0% 95.0% 50% 5.0% 2010.0003 JAN 11.2 9.2 7.7 4.9 4.3 3.7 2010.0837 FEB 14.7 10.0 6.9 5.3 4.0 2.5 2010.1670 MAR 17.8 11.0 5.6 5.6 3.8 1.6 2010.2503 APR 21.0 12.3 5.6 5.6 3.5 0.7 2010.3337 MAY 25.5 13.5 6.2 5.9 3.6 0.2 2010.4170 JUN 31.3 14.8 5.4 6.5 3.8 0.4 2010.5003 JUL 37.9 17.0 3.9 6.8 4.0 0.7 2010.5837 AUG 44.7 19.8 4.1 7.1 4.2 1.1 2010.6670 SEP 50.8 22.6 5.1 7.0 4.0 1.4 2010.7503 OCT 57.0 25.4 7.2 6.6 3.7 1.1 2010.8337 NOV 64.7 28.1 8.5 6.5 3.6 1.4 2010.9170 DEC 73.1 30.5 8.4 6.9 3.8 1.7 2011.0003 JAN 80.7 33.3 8.7 7.1 4.1 1.9 2011.0837 FEB 87.7 36.1 9.4 8.4 4.8 2.6 2011.1670 MAR 94.7 38.7 9.8 9.0 5.5 3.3 2011.2503 APR 102.2 41.6 10.7 9.1 6.0 3.6 2011.3337 MAY 106.4 44.2 12.3 9.5 6.5 3.9 2011.4170 JUN 109.5 47.0 14.8 10.4 7.0 3.8 2011.5003 JUL 113.5 49.6 15.9 11.3 7.3 3.7 2011.5837 AUG 116.9 51.3 15.4 11.3 7.5 3.5 2011.6670 SEP 120.6 53.0 15.7 11.8 7.8 3.5 2011.7503 OCT 126.1 54.9 17.5 12.7 8.4 3.8 2011.8337 NOV 130.7 57.4 19.3 13.8 8.9 4.0 2011.9170 DEC 134.0 60.4 20.9 14.4 9.4 4.2 2012.0003 JAN 139.2 63.3 23.5 14.8 10.0 4.2 2012.0837 FEB 144.8 65.8 27.2 15.6 10.3 4.2 2012.1670 MAR 148.7 68.2 28.5 16.1 10.5 4.4 2012.2503 APR 152.1 70.8 30.8 16.6 10.6 4.6 2012.3337 MAY 155.9 73.2 31.6 17.6 10.7 4.5 2012.4170 JUN 159.0 75.0 31.6 17.9 11.0 4.7 2012.5003 JUL 161.7 76.9 32.4 17.8 11.6 5.8 2012.5837 AUG 164.5 78.8 34.3 18.2 12.4 7.1 2012.6670 SEP 167.0 80.6 37.8 18.3 12.7 8.1 2012.7503 OCT 167.4 82.0 38.5 18.0 12.7 8.5 2012.8337 NOV 167.8 83.2 38.6 18.1 12.8 8.9 2012.9170 DEC 169.8 84.2 38.4 17.8 12.7 8.9 2013.0003 JAN 171.3 84.1 38.4 16.8 12.3 8.4 2013.0837 FEB 169.5 83.8 39.9 15.9 12.1 8.5 2013.1670 MAR 166.7 84.3 42.2 14.7 11.3 7.4 2013.2503 APR 164.0 85.3 43.1 13.7 10.2 6.2 2013.3337 MAY 162.7 85.9 41.9 13.6 9.8 6.2 2013.4170 JUN 162.4 85.9 39.6 14.4 9.6 6.0 2013.5003 JUL 161.8 85.9 39.3 15.3 9.5 5.3 2013.5837 AUG 161.5 86.2 40.1 15.8 9.5 5.1 2013.6670 SEP 161.2 86.3 40.3 16.6 9.6 4.8 2013.7503 OCT 160.7 86.1 39.0 17.0 9.6 4.5 2013.8337 NOV 158.9 85.2 36.3 16.8 10.0 5.2 2013.9170 DEC 157.7 84.6 34.9 16.9 10.2 5.5 2014.0003 JAN 156.6 84.2 35.1 16.3 10.3 5.9 2014.0837 FEB 154.6 83.3 34.9 14.9 10.6 6.6 2014.1670 MAR 151.5 81.7 33.8 16.5 11.1 7.2 2014.2503 APR 149.0 80.3 32.9 17.8 11.7 8.0 2014.3337 MAY 146.3 79.4 32.0 18.3 12.1 7.8 2014.4170 JUN 142.0 78.4 30.8 18.2 12.4 7.8 2014.5003 JUL 138.6 77.0 30.0 17.9 12.5 8.0 2014.5837 AUG 135.6 75.7 29.5 16.9 11.8 7.4 2014.6670 SEP 134.4 75.0 29.6 16.9 11.4 6.8 2014.7503 OCT 134.2 74.7 30.4 17.4 11.5 6.6 2014.8337 NOV 131.7 74.0 31.4 17.0 11.2 6.2 2014.9170 DEC 130.5 72.7 30.0 16.4 10.9 5.7 2015.0003 JAN 130.1 71.6 29.7 16.0 10.8 5.3 2015.0837 FEB 127.7 70.5 30.1 15.7 10.9 5.1 2015.1670 MAR 124.4 69.3 28.4 14.9 11.4 5.6 2015.2503 APR 120.4 68.0 26.4 15.6 11.6 5.9 2015.3337 MAY 116.2 66.7 25.4 16.3 11.8 6.8 2015.4170 JUN 112.9 65.6 24.7 16.8 12.3 7.3 2015.5003 JUL 111.0 64.4 24.1 16.8 12.9 7.8 2015.5837 AUG 107.8 63.1 23.5 16.7 13.2 8.4 2015.6670 SEP 102.0 61.4 23.3 17.8 13.4 8.9 2015.7503 OCT 95.6 59.4 23.5 18.6 13.5 9.5 2015.8337 NOV 91.7 57.5 23.8 18.9 13.7 10.6 2015.9170 DEC 90.2 55.5 22.7 18.7 13.9 10.2 2016.0003 JAN 89.1 53.8 21.9 18.3 14.0 9.9 2016.0837 FEB 86.9 52.5 22.6 18.1 13.8 9.4 2016.1670 MAR 84.9 51.2 22.7 18.2 13.6 9.1 2016.2503 APR 81.7 50.0 22.8 18.4 13.2 8.8 2016.3337 MAY 78.8 48.8 21.0 18.3 12.6 8.1 2016.4170 JUN 75.7 47.6 19.5 18.1 11.8 6.6 2016.5003 JUL 70.4 45.7 17.9 17.7 10.8 4.9 2016.5837 AUG 69.2 44.0 16.2 17.3 10.0 4.2 2016.6670 SEP 69.4 42.9 14.4 17.3 9.6 3.8 2016.7503 OCT 68.6 41.4 13.2 17.2 9.4 3.4 2016.8337 NOV 68.4 40.1 11.9 16.7 9.0 3.2 2016.9170 DEC 67.9 39.0 10.4 16.1 8.9 3.4 2017.0003 JAN 66.6 38.0 9.5 15.6 9.0 3.8 2017.0837 FEB 64.6 37.2 8.7 15.1 9.2 4.3 2017.1670 MAR 61.9 36.3 8.1 15.1 9.7 4.7 2017.2503 APR 57.9 35.4 8.2 15.2 10.2 5.1 2017.3337 MAY 53.0 34.1 8.2 15.7 10.9 5.9 2017.4170 JUN 50.1 32.9 7.7 16.3 11.7 7.0 2017.5003 JUL 50.3 32.3 7.5 17.1 12.3 8.0 2017.5837 AUG 49.5 31.6 7.4 17.9 12.6 8.6 2017.6670 SEP 46.9 30.1 7.2 18.5 12.9 9.0 2017.7503 OCT 44.4 28.4 7.3 19.0 13.2 9.2 2017.8337 NOV 42.3 27.0 7.1 19.3 13.6 9.3 2017.9170 DEC 41.1 25.7 6.4 19.5 14.2 9.7 2018.0003 JAN 39.6 24.1 5.6 19.8 15.2 10.3 2018.0837 FEB 38.4 22.6 5.1 20.0 16.1 10.9 2018.1670 MAR 37.2 21.3 4.3 21.1 16.8 11.1 2018.2503 APR 35.4 20.3 4.0 21.5 17.1 11.1 2018.3337 MAY 33.6 19.2 3.7 21.3 16.9 11.2 2018.4170 JUN 31.9 18.1 3.4 20.7 16.7 11.2 2018.5003 JUL 30.1 17.0 3.1 20.5 16.8 11.8 2018.5837 AUG 28.4 16.0 2.8 20.9 17.3 12.7 2018.6670 SEP 26.8 15.0 2.5 21.1 17.4 13.0 2018.7503 OCT 25.2 14.0 2.2 20.9 17.3 13.1 2018.8337 NOV 23.6 13.0 2.0 20.4 16.8 12.8 2018.9170 DEC 22.1 12.1 1.7 19.3 15.9 12.2 2019.0003 JAN 20.7 11.3 1.5 18.2 15.0 11.5 2019.0837 FEB 19.4 10.4 1.2 17.2 14.2 10.8 2019.1670 MAR 18.2 9.7 1.0 16.2 13.3 10.2 2019.2503 APR 17.0 9.0 0.8 15.3 12.5 9.6 2019.3337 MAY 16.0 8.3 0.7 14.4 11.8 9.1 2019.4170 JUN 15.0 7.8 0.5 13.6 11.1 8.5 2019.5003 JUL 14.2 7.3 0.4 12.9 10.5 8.1 2019.5837 AUG 13.5 6.8 0.2 12.2 10.0 7.7 2019.6670 SEP 13.0 6.5 0.1 11.7 9.5 7.4 2019.7503 OCT 12.6 6.3 0.1 11.4 9.2 7.1 2019.8337 NOV 12.4 6.1 0.0 11.1 9.0 7.0 2019.9170 DEC 12.3 6.1 0.0 11.1 9.0 6.9 2020.0003 JAN 12.9 6.5 0.4 11.3 9.0 6.9 2020.0837 FEB 14.2 7.2 0.9 11.6 9.2 7.1 2020.1670 MAR 15.4 7.8 1.2 11.7 9.3 7.4 2020.2503 APR 16.6 8.5 1.7 11.9 9.4 7.5 2020.3337 MAY 18.1 9.3 1.8 12.0 9.5 7.5 2020.4170 JUN 20.6 10.2 2.3 12.1 9.6 7.3 2020.5003 JUL 23.0 11.2 2.9 12.2 9.7 7.2 2020.5837 AUG 25.1 12.3 3.1 12.5 9.9 7.1 2020.6670 SEP 28.3 13.6 3.2 12.8 10.1 7.0 2020.7503 OCT 32.2 15.1 3.5 13.2 10.5 7.2 2020.8337 NOV 38.2 16.9 3.5 13.7 10.8 7.6 2020.9170 DEC 43.7 19.0 3.5 14.5 11.1 7.9 2021.0003 JAN 47.9 21.0 4.2 15.7 11.4 7.7 2021.0837 FEB 54.1 23.4 4.3 16.1 11.6 7.7 2021.1670 MAR 60.7 25.9 4.3 16.3 11.8 7.6 2021.2503 APR 66.8 28.4 4.8 16.8 12.0 7.6 2021.3337 MAY 74.4 31.2 4.8 18.0 12.3 7.6 2021.4170 JUN 83.1 34.5 5.2 18.9 12.6 7.7 2021.5003 JUL 89.9 37.8 5.8 19.1 12.7 7.7 2021.5837 AUG 95.1 41.3 6.8 19.2 12.9 7.8 2021.6670 SEP 100.0 44.8 7.7 19.0 13.1 7.7 2021.7503 OCT 105.0 48.2 9.1 18.6 13.1 7.7 2021.8337 NOV 110.5 51.5 9.8 18.5 13.2 7.8 2021.9170 DEC 116.5 54.9 9.9 18.9 13.4 8.0 2022.0003 JAN 122.0 58.5 11.2 18.8 13.5 8.2 2022.0837 FEB 126.8 62.1 12.4 17.8 13.5 8.6 2022.1670 MAR 134.1 65.8 13.4 17.9 13.7 8.7 2022.2503 APR 141.4 69.4 14.6 18.5 13.9 8.7 2022.3337 MAY 146.1 72.7 15.1 19.1 14.2 9.0 2022.4170 JUN 147.9 75.6 15.6 19.6 14.6 9.4 2022.5003 JUL 151.0 78.5 16.2 20.3 14.9 9.6 2022.5837 AUG 154.7 80.9 16.7 20.3 15.1 9.6 2022.6670 SEP 158.4 83.0 17.1 20.3 15.1 9.8 2022.7503 OCT 163.8 85.3 17.1 20.5 15.2 10.0 2022.8337 NOV 167.3 87.7 16.7 20.8 15.4 10.5 2022.9170 DEC 169.1 90.1 16.4 21.2 15.4 11.1 2023.0003 JAN 172.9 92.3 16.8 21.3 15.3 11.6 2023.0837 FEB 177.6 94.2 17.5 21.4 15.1 11.3 2023.1670 MAR 180.4 96.2 18.7 21.6 15.0 11.2 2023.2503 APR 182.4 98.4 20.6 22.0 15.0 10.7 2023.3337 MAY 185.0 100.2 21.8 22.8 14.9 10.2 2023.4170 JUN 187.4 101.3 23.1 22.5 14.7 9.9 2023.5003 JUL 189.5 102.2 25.4 21.3 14.5 10.1 2023.5837 AUG 190.7 102.4 28.1 20.6 14.3 10.1 2023.6670 SEP 192.2 102.8 30.7 20.1 14.2 10.3 2023.7503 OCT 192.5 103.6 32.1 19.6 14.1 10.6 2023.8337 NOV 192.1 104.1 33.4 19.5 14.0 10.6 2023.9170 DEC 193.4 104.4 35.7 19.3 14.0 10.5 2024.0003 JAN 193.9 103.6 37.4 19.1 14.2 10.5 2024.0837 FEB 190.8 102.1 39.6 18.9 14.6 10.5 2024.1670 MAR 186.3 101.2 41.2 18.9 14.7 10.3 2024.2503 APR 181.9 100.7 42.7 19.5 14.6 9.8 2024.3337 MAY 179.6 100.4 43.9 20.4 14.7 10.2 2024.4170 JUN 178.9 100.1 43.8 22.0 15.0 10.7 2024.5003 JUL 177.8 99.7 43.3 23.4 15.3 10.7 2024.5837 AUG 176.5 99.1 44.0 24.0 15.4 10.9 2024.6670 SEP 175.3 98.5 45.9 25.1 15.7 11.1 2024.7503 OCT 174.5 98.0 46.0 25.6 15.9 11.3 2024.8337 NOV 173.4 97.4 45.1 24.9 15.9 11.5 2024.9170 DEC 172.3 96.6 44.4 24.8 15.9 11.7 2025.0003 JAN 170.7 95.7 44.9 23.9 15.8 11.9 2025.0837 FEB 168.1 94.1 45.4 22.1 15.8 11.8 2025.1670 MAR 164.2 92.1 44.3 22.4 15.9 12.0 2025.2503 APR 161.0 90.3 43.7 23.1 16.0 11.8 2025.3337 MAY 157.9 89.1 44.7 23.1 16.0 11.1 2025.4170 JUN 153.9 87.8 45.7 22.6 16.0 10.8 2025.5003 JUL 150.5 86.2 44.6 22.0 15.8 10.8 2025.5837 AUG 146.4 84.3 42.6 21.9 15.8 10.8 2025.6670 SEP 142.9 82.9 41.6 22.7 16.1 10.8 2025.7503 OCT 142.0 81.8 41.3 23.7 16.5 10.8 2025.8337 NOV 138.7 80.3 39.3 23.9 16.7 10.8 2025.9170 DEC 136.4 78.4 35.0 23.9 17.0 10.7 2026.0003 JAN 135.3 76.6 34.1 23.9 17.1 10.6 2026.0837 FEB 132.3 74.9 35.4 23.5 17.2 10.3 2026.1670 MAR 128.8 73.5 34.6 22.5 17.2 10.5 2026.2503 APR 124.8 72.3 32.7 22.7 17.2 10.7 2026.3337 MAY 120.7 71.1 31.7 23.0 17.4 11.4 2026.4170 JUN 117.2 69.7 30.9 23.1 17.6 11.9 2026.5003 JUL 114.8 68.0 29.4 22.5 17.8 12.0 2026.5837 AUG 110.8 66.0 27.7 21.7 17.6 12.1 2026.6670 SEP 104.4 63.7 26.7 21.2 17.4 12.3 2026.7503 OCT 97.6 61.3 26.3 21.7 17.0 12.5 2026.8337 NOV 93.7 59.4 26.6 21.7 16.9 13.3 2026.9170 DEC 92.5 57.7 25.8 22.1 16.9 13.1 2027.0003 JAN 91.4 56.1 24.3 22.6 17.0 12.8 2027.0837 FEB 88.9 54.7 24.4 22.3 16.8 13.1 2027.1670 MAR 86.8 53.1 23.8 22.4 16.5 12.7 2027.2503 APR 83.1 51.4 22.7 22.7 16.2 12.5 2027.3337 MAY 79.8 49.8 21.9 22.9 15.8 12.1 2027.4170 JUN 76.3 48.2 20.4 23.5 15.6 11.2 2027.5003 JUL 71.0 46.4 18.9 24.1 15.4 10.5 2027.5837 AUG 69.8 44.7 16.7 24.8 15.3 10.7 2027.6670 SEP 70.1 43.5 14.9 25.3 15.3 10.8 2027.7503 OCT 69.7 42.3 13.7 25.6 15.3 10.6 2027.8337 NOV 69.6 41.1 11.9 25.4 15.3 10.8 2027.9170 DEC 68.8 39.7 10.4 24.9 15.2 11.0 2028.0003 JAN 66.8 38.2 9.5 24.0 15.0 11.1 2028.0837 FEB 64.1 36.8 8.7 23.0 14.9 11.3 2028.1670 MAR 60.9 35.5 7.9 22.5 15.0 11.2 2028.2503 APR 56.4 34.1 7.8 22.1 15.1 11.1 2028.3337 MAY 52.1 32.5 7.9 21.8 15.2 11.2 2028.4170 JUN 49.0 31.3 7.6 21.4 15.3 11.4 2028.5003 JUL 49.8 30.5 7.5 20.7 15.2 11.5 2028.5837 AUG 49.0 29.5 7.4 19.9 14.9 11.3 2028.6670 SEP 46.4 28.2 7.1 20.0 14.7 11.1 2028.7503 OCT 44.0 26.8 6.5 20.1 14.6 10.8 2028.8337 NOV 42.0 25.7 6.5 19.9 14.3 10.1 2028.9170 DEC 40.9 24.9 6.1 19.5 14.2 9.6 2029.0003 JAN 39.5 23.8 5.5 19.0 14.1 9.1 2029.0837 FEB 38.8 22.8 5.2 18.3 14.1 8.6 2029.1670 MAR 38.1 21.9 4.6 17.3 14.0 8.0 2029.2503 APR 37.7 21.0 3.8 17.4 13.8 7.5 2029.3337 MAY 36.9 20.0 3.6 17.5 13.7 7.6 2029.4170 JUN 35.9 19.2 3.5 17.6 13.7 7.8 2029.5003 JUL 34.7 18.3 3.3 17.5 13.6 8.3 2029.5837 AUG 33.3 17.4 3.2 17.7 13.5 8.6 2029.6670 SEP 31.6 16.5 2.6 18.1 13.4 8.5 2029.7503 OCT 29.7 15.5 2.0 17.9 13.2 8.6 2029.8337 NOV 27.1 14.8 1.6 17.6 12.9 8.5 2029.9170 DEC 24.5 13.8 1.6 17.3 12.6 8.5 2030.0003 JAN 22.1 12.6 1.3 16.3 12.2 8.4 2030.0837 FEB 20.3 11.5 0.9 14.8 11.8 8.4 2030.1670 MAR 19.2 10.5 0.6 13.8 11.4 8.3 2030.2503 APR 18.9 9.7 0.6 13.9 11.0 8.2 2030.3337 MAY 18.5 9.1 0.5 13.6 10.6 8.2 2030.4170 JUN 18.2 8.5 0.4 13.2 10.3 7.9 2030.5003 JUL 16.8 8.0 0.3 12.9 9.9 7.4 2030.5837 AUG 15.9 7.5 0.2 12.6 9.7 7.1 2030.6670 SEP 15.8 7.0 0.1 11.9 9.5 7.3 2030.7503 OCT 15.0 6.5 0.0 11.4 9.4 7.1