TABLE 4 ESTIMATES OF 13-MONTH SMOOTH SOLAR ACTIVITY FOR BALANCE OF CYCLE 24 WITH A MEAN CYCLE GIVEN FOR CYCLE 25 TIME SUNSPOT NUMBERS GEOMAGNETIC INDEX (Ap) PERCENTILE PERCENTILE 95.0% 50% 5.0% 95.0% 50% 5.0% 2018.5003 JUL 8.5 6.9 4.9 7.5 7.1 6.6 2018.5837 AUG 11.0 6.3 3.0 8.0 7.1 6.4 2018.6670 SEP 12.6 5.9 1.4 8.5 7.1 6.2 2018.7503 OCT 13.4 5.8 0.0 9.0 7.3 5.5 2018.8337 NOV 14.2 6.2 0.0 9.4 7.5 5.3 2018.9170 DEC 14.5 6.2 0.0 9.8 7.6 5.4 2019.0003 JAN 14.4 5.8 0.0 9.6 7.8 5.4 2019.0837 FEB 14.6 5.3 0.0 9.7 8.0 5.7 2019.1670 MAR 15.3 5.0 0.0 10.6 8.4 6.1 2019.2503 APR 16.3 4.9 0.0 11.4 8.7 6.3 2019.3337 MAY 16.9 4.8 0.0 11.6 8.8 6.4 2019.4170 JUN 17.2 4.7 0.0 11.3 8.5 6.2 2019.5003 JUL 16.6 4.6 0.0 10.9 8.1 6.0 2019.5837 AUG 14.7 4.4 0.0 10.5 7.8 5.6 2019.6670 SEP 12.3 4.0 0.0 10.0 7.8 5.6 2019.7503 OCT 11.1 3.5 0.0 9.7 7.8 5.6 2019.8337 NOV 10.3 3.2 0.0 9.6 7.7 5.5 2019.9170 DEC 10.3 3.2 0.0 9.6 7.7 5.5 2020.0003 JAN 11.3 3.8 0.7 9.8 7.8 5.5 2020.0837 FEB 13.2 4.9 1.4 10.1 8.0 5.7 2020.1670 MAR 14.9 6.0 2.0 10.2 8.1 6.0 2020.2503 APR 17.5 7.0 2.8 10.4 8.2 6.1 2020.3337 MAY 20.4 8.2 3.2 10.5 8.3 6.1 2020.4170 JUN 25.2 9.8 3.9 10.6 8.4 5.8 2020.5003 JUL 28.8 11.3 5.0 10.7 8.4 5.7 2020.5837 AUG 32.5 13.1 5.4 11.0 8.6 5.6 2020.6670 SEP 38.1 15.2 5.5 11.3 8.9 5.5 2020.7503 OCT 45.2 17.5 5.8 11.7 9.3 5.7 2020.8337 NOV 55.7 20.4 5.7 12.2 9.6 6.1 2020.9170 DEC 64.7 23.7 5.9 13.1 9.9 6.4 2021.0003 JAN 71.7 26.9 7.0 14.2 10.2 6.2 2021.0837 FEB 81.9 30.5 7.1 14.6 10.4 6.2 2021.1670 MAR 93.2 34.6 7.1 14.8 10.6 6.1 2021.2503 APR 103.3 38.6 7.9 15.3 10.7 6.1 2021.3337 MAY 115.7 42.9 8.0 16.5 11.0 6.1 2021.4170 JUN 130.3 48.0 8.6 17.4 11.3 6.2 2021.5003 JUL 140.5 53.2 9.7 17.6 11.5 6.2 2021.5837 AUG 147.4 58.7 11.4 17.7 11.7 6.3 2021.6670 SEP 154.5 64.2 12.9 17.5 11.9 6.2 2021.7503 OCT 162.4 69.6 15.1 17.1 11.9 6.2 2021.8337 NOV 171.1 74.8 16.4 17.0 12.0 6.3 2021.9170 DEC 180.5 80.1 16.5 17.4 12.2 6.5 2022.0003 JAN 189.3 85.8 18.7 17.3 12.2 6.7 2022.0837 FEB 196.9 91.6 20.6 16.3 12.3 7.1 2022.1670 MAR 204.9 97.5 22.3 16.4 12.5 7.2 2022.2503 APR 209.7 103.2 24.2 17.0 12.7 7.3 2022.3337 MAY 216.2 108.6 25.1 17.6 13.0 7.5 2022.4170 JUN 217.6 113.4 26.1 18.1 13.4 7.9 2022.5003 JUL 218.1 118.1 27.1 18.8 13.7 8.1 2022.5837 AUG 223.4 122.0 27.8 18.8 13.8 8.1 2022.6670 SEP 225.9 125.3 28.5 18.8 13.9 8.3 2022.7503 OCT 228.4 128.9 28.5 19.0 14.0 8.5 2022.8337 NOV 231.6 132.6 27.9 19.3 14.1 9.0 2022.9170 DEC 234.0 136.4 27.3 19.7 14.2 9.6 2023.0003 JAN 240.4 139.9 28.0 19.8 14.0 10.2 2023.0837 FEB 248.0 142.8 29.0 19.9 13.9 9.8 2023.1670 MAR 252.9 145.8 31.1 20.1 13.8 9.7 2023.2503 APR 257.1 149.1 34.3 20.5 13.8 9.2 2023.3337 MAY 261.8 151.8 36.2 21.3 13.7 8.8 2023.4170 JUN 265.2 153.7 38.5 21.0 13.5 8.5 2023.5003 JUL 267.3 155.1 42.4 19.8 13.3 8.6 2023.5837 AUG 268.4 155.3 46.7 19.1 13.1 8.6 2023.6670 SEP 269.9 155.9 51.3 18.6 13.0 8.9 2023.7503 OCT 269.5 157.1 53.5 18.1 12.9 9.1 2023.8337 NOV 268.4 158.0 55.6 18.0 12.8 9.1 2023.9170 DEC 269.7 158.6 59.5 17.8 12.8 9.0 2024.0003 JAN 269.2 157.2 62.2 17.6 13.0 9.0 2024.0837 FEB 263.6 155.0 66.0 17.4 13.3 9.0 2024.1670 MAR 256.9 153.6 68.7 17.4 13.5 8.8 2024.2503 APR 250.9 153.1 71.3 18.0 13.4 8.4 2024.3337 MAY 247.4 153.0 73.2 18.9 13.5 8.7 2024.4170 JUN 245.6 152.7 72.9 20.5 13.8 9.2 2024.5003 JUL 244.0 152.2 72.1 21.9 14.1 9.2 2024.5837 AUG 242.7 151.4 73.3 22.5 14.2 9.4 2024.6670 SEP 240.6 150.5 76.5 23.6 14.5 9.6 2024.7503 OCT 239.0 149.7 76.7 24.1 14.7 9.8 2024.8337 NOV 237.0 148.8 75.1 23.4 14.7 10.0 2024.9170 DEC 235.8 147.6 74.0 23.3 14.7 10.2 2025.0003 JAN 233.4 146.2 74.9 22.5 14.6 10.4 2025.0837 FEB 229.1 143.9 75.7 20.6 14.6 10.3 2025.1670 MAR 224.0 140.7 73.7 20.9 14.7 10.5 2025.2503 APR 219.8 137.8 72.9 21.6 14.8 10.3 2025.3337 MAY 215.1 135.7 74.5 21.7 14.8 9.6 2025.4170 JUN 209.0 133.6 76.2 21.1 14.7 9.3 2025.5003 JUL 204.1 130.9 74.2 20.5 14.6 9.3 2025.5837 AUG 198.4 127.9 70.9 20.4 14.6 9.3 2025.6670 SEP 194.0 125.6 69.3 21.2 14.9 9.3 2025.7503 OCT 192.4 123.9 68.8 22.2 15.3 9.3 2025.8337 NOV 187.2 121.6 65.5 22.4 15.5 9.3 2025.9170 DEC 184.3 118.7 58.3 22.4 15.8 9.2 2026.0003 JAN 182.6 115.7 56.8 22.4 15.9 9.1 2026.0837 FEB 177.7 113.1 58.9 22.0 16.0 8.8 2026.1670 MAR 172.1 110.9 57.6 21.1 16.0 9.0 2026.2503 APR 166.4 109.0 54.5 21.3 16.0 9.2 2026.3337 MAY 160.8 107.2 52.9 21.5 16.1 9.9 2026.4170 JUN 156.1 105.1 51.5 21.6 16.4 10.4 2026.5003 JUL 152.8 102.4 49.0 21.0 16.5 10.5 2026.5837 AUG 147.6 99.4 46.2 20.2 16.4 10.7 2026.6670 SEP 138.6 95.8 44.6 19.7 16.1 10.8 2026.7503 OCT 130.3 92.1 44.0 20.2 15.8 11.0 2026.8337 NOV 129.1 89.0 44.4 20.2 15.7 11.8 2026.9170 DEC 127.6 86.2 42.9 20.6 15.7 11.6 2027.0003 JAN 123.3 83.7 40.5 21.1 15.8 11.4 2027.0837 FEB 118.8 81.4 40.7 20.8 15.6 11.6 2027.1670 MAR 114.1 78.8 39.7 20.9 15.3 11.3 2027.2503 APR 108.7 76.1 37.9 21.2 15.0 11.0 2027.3337 MAY 107.8 73.5 36.4 21.4 14.6 10.6 2027.4170 JUN 108.8 71.0 34.0 22.0 14.4 9.8 2027.5003 JUL 107.3 68.2 31.6 22.6 14.2 9.0 2027.5837 AUG 105.9 65.4 27.8 23.3 14.1 9.2 2027.6670 SEP 103.5 63.4 24.8 23.8 14.1 9.3 2027.7503 OCT 99.5 61.5 22.9 24.1 14.1 9.2 2027.8337 NOV 95.6 59.5 19.9 23.9 14.0 9.3 2027.9170 DEC 92.3 57.2 17.3 23.4 13.9 9.5 2028.0003 JAN 91.5 54.9 15.8 22.5 13.8 9.6 2028.0837 FEB 90.4 52.8 14.5 21.5 13.7 9.8 2028.1670 MAR 87.4 50.7 13.2 21.0 13.8 9.7 2028.2503 APR 83.5 48.5 13.0 20.6 13.9 9.6 2028.3337 MAY 78.4 46.2 13.2 20.3 14.0 9.7 2028.4170 JUN 76.7 44.3 12.6 19.9 14.1 9.9 2028.5003 JUL 77.0 42.9 12.5 19.2 14.0 10.0 2028.5837 AUG 74.0 41.4 12.3 18.4 13.7 9.8 2028.6670 SEP 69.5 39.4 11.9 18.5 13.5 9.6 2028.7503 OCT 65.7 37.1 10.9 18.7 13.3 9.3 2028.8337 NOV 61.9 35.4 10.7 18.4 13.1 8.7 2028.9170 DEC 60.3 34.0 10.1 18.0 13.0 8.2 2029.0003 JAN 57.7 32.4 9.1 17.5 12.9 7.7 2029.0837 FEB 56.5 30.7 8.6 16.8 12.9 7.2 2029.1670 MAR 55.1 29.1 7.7 15.9 12.8 6.5 2029.2503 APR 54.2 27.6 6.4 15.9 12.6 6.1 2029.3337 MAY 52.8 26.0 5.9 16.0 12.5 6.2 2029.4170 JUN 50.9 24.5 5.8 16.1 12.4 6.4 2029.5003 JUL 48.8 23.1 5.5 16.0 12.4 6.8 2029.5837 AUG 46.6 21.7 5.4 16.2 12.3 7.1 2029.6670 SEP 43.7 20.1 4.2 16.6 12.2 7.1 2029.7503 OCT 40.5 18.5 3.2 16.5 12.0 7.1 2029.8337 NOV 36.0 17.3 2.7 16.1 11.7 7.0 2029.9170 DEC 30.5 15.7 2.5 15.8 11.4 7.0 2030.0003 JAN 26.8 13.8 2.1 14.8 11.0 6.9 2030.0837 FEB 25.0 12.0 1.4 13.3 10.6 6.9 2030.1670 MAR 23.9 10.4 1.1 12.3 10.2 6.8 2030.2503 APR 23.5 9.1 0.9 12.4 9.8 6.7 2030.3337 MAY 22.8 8.0 0.9 12.1 9.4 6.7 2030.4170 JUN 22.1 7.1 0.6 11.7 9.0 6.4 2030.5003 JUL 19.8 6.2 0.4 11.4 8.7 5.9 2030.5837 AUG 17.2 5.4 0.3 11.1 8.5 5.6 2030.6670 SEP 15.3 4.6 0.1 10.4 8.3 5.8 2030.7503 OCT 13.6 3.8 0.0 9.9 8.2 5.7