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% 2011.0837 FEB 35.9 33.3 30.3 8.1 7.2 6.4 2011.1670 MAR 40.0 35.4 28.7 9.0 7.9 6.7 2011.2503 APR 47.0 37.7 26.8 10.3 8.3 6.8 2011.3337 MAY 53.3 40.0 27.3 11.3 8.8 7.2 2011.4170 JUN 60.4 42.6 26.7 11.6 9.0 6.9 2011.5003 JUL 66.4 44.9 25.0 11.2 9.1 6.4 2011.5837 AUG 71.2 46.5 25.7 10.9 9.2 6.2 2011.6670 SEP 75.7 48.1 25.6 11.2 9.5 6.0 2011.7503 OCT 81.7 49.9 23.2 11.8 9.7 5.9 2011.8337 NOV 89.0 51.7 20.1 12.6 10.0 5.6 2011.9170 DEC 95.0 54.0 16.4 13.0 10.1 5.2 2012.0003 JAN 99.8 56.1 13.2 13.0 10.3 4.8 2012.0837 FEB 103.1 57.9 11.7 13.4 10.5 4.4 2012.1670 MAR 106.5 60.0 11.4 13.8 10.5 4.5 2012.2503 APR 111.0 62.4 12.6 14.1 10.5 4.4 2012.3337 MAY 114.8 64.5 13.0 14.8 10.4 4.1 2012.4170 JUN 116.2 66.2 12.5 15.2 10.6 4.1 2012.5003 JUL 114.9 67.7 12.0 15.4 11.1 5.0 2012.5837 AUG 114.4 69.1 11.4 15.7 11.5 5.9 2012.6670 SEP 114.1 70.3 12.7 15.8 11.8 6.6 2012.7503 OCT 117.2 71.4 14.7 15.5 11.7 7.0 2012.8337 NOV 119.9 72.5 15.8 15.6 11.8 7.3 2012.9170 DEC 120.0 73.4 16.6 15.3 11.7 7.3 2013.0003 JAN 120.1 73.3 16.6 14.5 11.6 7.2 2013.0837 FEB 119.8 73.0 17.5 14.8 11.6 7.7 2013.1670 MAR 119.9 73.6 19.2 14.5 11.2 7.6 2013.2503 APR 119.9 74.7 20.8 13.7 10.5 6.8 2013.3337 MAY 119.5 75.5 21.0 13.8 10.3 7.0 2013.4170 JUN 118.4 75.5 19.8 14.7 10.2 6.9 2013.5003 JUL 117.0 75.5 17.6 15.6 10.1 6.8 2013.5837 AUG 117.0 75.8 15.7 16.2 10.3 7.1 2013.6670 SEP 118.0 76.1 14.5 17.1 10.4 7.1 2013.7503 OCT 118.5 76.1 12.3 17.3 10.3 6.7 2013.8337 NOV 120.1 75.5 10.6 16.9 10.6 7.0 2013.9170 DEC 122.5 75.1 9.6 17.1 10.8 7.1 2014.0003 JAN 121.2 74.7 9.6 16.7 11.0 7.2 2014.0837 FEB 118.5 73.6 8.8 15.1 11.1 7.1 2014.1670 MAR 116.4 72.1 7.8 15.1 11.3 7.2 2014.2503 APR 116.2 70.8 7.4 15.6 11.7 7.6 2014.3337 MAY 116.2 70.2 7.8 16.2 12.1 8.1 2014.4170 JUN 115.9 69.7 8.6 16.7 12.5 8.2 2014.5003 JUL 115.6 68.6 9.5 17.1 12.7 8.5 2014.5837 AUG 117.6 67.6 11.1 16.3 12.4 8.3 2014.6670 SEP 120.6 67.2 13.4 15.9 12.3 7.9 2014.7503 OCT 121.5 67.0 15.2 16.5 12.4 7.8 2014.8337 NOV 119.8 66.6 17.2 16.1 12.3 7.6 2014.9170 DEC 118.5 65.4 18.8 15.8 12.4 7.4 2015.0003 JAN 118.2 64.1 19.9 16.0 12.5 7.2 2015.0837 FEB 116.5 63.3 20.3 16.9 12.9 7.1 2015.1670 MAR 114.1 62.6 19.6 18.2 13.5 7.6 2015.2503 APR 110.9 61.9 18.8 19.2 14.0 8.2 2015.3337 MAY 107.2 61.0 18.7 20.0 14.5 9.2 2015.4170 JUN 104.6 60.2 18.6 20.4 15.0 9.9 2015.5003 JUL 103.3 59.3 18.3 20.2 15.3 10.2 2015.5837 AUG 100.0 58.0 18.0 20.0 15.7 10.6 2015.6670 SEP 94.1 56.3 17.9 20.4 15.9 11.1 2015.7503 OCT 87.8 54.5 18.2 21.1 16.0 11.6 2015.8337 NOV 84.5 53.0 19.0 21.3 16.2 12.8 2015.9170 DEC 83.3 51.2 18.4 21.5 16.5 12.5 2016.0003 JAN 82.5 49.8 18.1 21.9 16.5 12.3 2016.0837 FEB 81.5 48.9 19.0 21.3 16.2 11.9 2016.1670 MAR 80.4 48.0 19.3 21.0 15.7 11.3 2016.2503 APR 78.1 47.0 19.2 20.9 15.1 10.6 2016.3337 MAY 75.6 46.0 17.6 20.8 14.5 9.7 2016.4170 JUN 73.0 44.9 16.7 20.9 14.0 8.4 2016.5003 JUL 70.7 43.4 15.2 20.9 13.3 6.9 2016.5837 AUG 70.2 41.9 13.8 20.7 12.7 6.1 2016.6670 SEP 69.2 40.8 12.7 20.7 12.4 5.6 2016.7503 OCT 67.0 39.4 11.9 20.8 12.3 5.3 2016.8337 NOV 66.2 38.2 11.3 20.5 12.1 5.2 2016.9170 DEC 65.5 36.9 10.6 19.9 12.0 5.4 2017.0003 JAN 64.1 35.9 9.7 19.3 12.0 5.9 2017.0837 FEB 62.5 35.1 8.8 18.9 12.3 6.7 2017.1670 MAR 59.9 34.2 8.0 19.0 12.8 7.2 2017.2503 APR 56.0 33.2 7.8 18.9 13.1 7.6 2017.3337 MAY 52.2 31.8 7.9 19.1 13.5 8.3 2017.4170 JUN 49.2 30.5 7.6 19.1 13.9 8.9 2017.5003 JUL 49.6 29.9 7.5 18.9 14.0 9.4 2017.5837 AUG 48.9 29.3 7.4 19.1 14.0 9.8 2017.6670 SEP 46.4 28.0 7.2 19.5 14.0 10.5 2017.7503 OCT 44.0 26.5 6.5 19.7 14.0 10.3 2017.8337 NOV 42.1 25.4 6.4 19.6 14.0 9.8 2017.9170 DEC 41.2 24.3 5.9 19.4 14.1 9.6 2018.0003 JAN 39.4 23.2 5.5 19.3 14.5 9.5 2018.0837 FEB 37.6 22.0 5.2 18.9 14.9 9.3 2018.1670 MAR 35.8 20.9 4.8 18.9 15.1 8.9 2018.2503 APR 34.0 19.8 4.4 18.8 15.0 8.6 2018.3337 MAY 32.3 18.7 4.1 18.7 14.9 8.7 2018.4170 JUN 30.6 17.6 3.7 18.4 14.9 8.9 2018.5003 JUL 28.9 16.6 3.4 18.2 15.1 9.5 2018.5837 AUG 27.3 15.5 3.1 18.6 15.4 10.1 2018.6670 SEP 25.7 14.5 2.7 18.8 15.5 10.4 2018.7503 OCT 24.2 13.6 2.4 18.8 15.5 10.5 2018.8337 NOV 22.7 12.6 2.1 18.5 15.2 10.4 2018.9170 DEC 21.3 11.8 1.9 17.7 14.5 10.0 2019.0003 JAN 20.0 10.9 1.6 16.8 13.8 9.6 2019.0837 FEB 18.8 10.2 1.3 16.0 13.1 9.3 2019.1670 MAR 17.6 9.4 1.1 15.2 12.4 8.9 2019.2503 APR 16.6 8.8 0.9 14.4 11.8 8.5 2019.3337 MAY 15.6 8.2 0.7 13.7 11.2 8.2 2019.4170 JUN 14.8 7.6 0.5 13.1 10.7 7.9 2019.5003 JUL 14.0 7.2 0.4 12.5 10.2 7.6 2019.5837 AUG 13.4 6.8 0.3 12.0 9.8 7.4 2019.6670 SEP 12.9 6.5 0.2 11.6 9.4 7.2 2019.7503 OCT 12.6 6.2 0.1 11.3 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