TABLE 4 ESTIMATES OF 13-MONTH SMOOTH SOLAR ACTIVITY FOR BALANCE OF CYCLE 23 CYCLE 24 AND BEGINNING OF CYCLE 25 TIME SUNSPOT NUMBERS GEOMAGNETIC INDEX (Ap) PERCENTILE PERCENTILE 95.0% 50% 5.0% 95.0% 50% 5.0% 2007.0833 FEB 13.3 11.8 9.7 9.1 8.8 8.1 2007.1667 MAR 14.3 11.6 8.1 9.4 8.7 7.5 2007.2500 APR 15.3 11.5 7.0 9.8 8.6 7.2 2007.3333 MAY 16.2 11.4 6.3 10.3 8.6 7.1 2007.4167 JUN 17.2 11.2 5.5 10.6 8.7 7.1 2007.5000 JUL 18.1 11.2 4.9 10.9 8.8 6.7 2007.5833 AUG 19.5 11.5 4.5 11.4 8.9 6.8 2007.6667 SEP 21.1 12.0 4.5 12.4 9.1 7.2 2007.7500 OCT 23.0 12.6 4.7 14.0 9.5 7.5 2007.8333 NOV 24.7 13.3 4.7 15.0 9.8 8.0 2007.9167 DEC 26.1 14.3 5.6 15.5 10.0 7.9 2008.0000 JAN 28.4 15.4 6.5 16.1 10.4 7.9 2008.0833 FEB 31.0 16.7 6.8 16.4 10.7 7.8 2008.1667 MAR 34.0 18.1 6.8 16.6 10.8 7.7 2008.2500 APR 37.7 19.6 7.4 17.0 10.9 7.8 2008.3333 MAY 42.2 21.6 8.6 17.2 11.0 8.0 2008.4167 JUN 47.1 23.8 9.5 17.3 11.3 8.3 2008.5000 JUL 51.6 26.1 10.2 17.6 11.6 8.6 2008.5833 AUG 55.2 28.3 10.9 17.9 12.0 9.0 2008.6667 SEP 57.4 30.6 11.6 18.0 12.5 9.6 2008.7500 OCT 59.4 33.0 11.7 17.5 12.8 10.0 2008.8333 NOV 65.2 35.7 11.2 16.8 13.0 10.0 2008.9167 DEC 72.5 38.5 11.0 16.5 13.1 10.0 2009.0000 JAN 79.8 41.3 11.1 16.5 13.3 10.0 2009.0833 FEB 87.8 44.3 11.1 17.0 13.5 9.9 2009.1667 MAR 97.3 47.4 11.2 17.6 13.6 9.5 2009.2500 APR 106.7 50.2 11.4 18.1 13.7 9.4 2009.3333 MAY 115.2 53.0 11.8 18.4 13.7 9.2 2009.4167 JUN 123.7 56.2 12.5 18.5 13.4 8.6 2009.5000 JUL 128.9 60.1 15.1 18.7 13.5 8.7 2009.5833 AUG 134.0 64.0 17.7 19.0 13.6 8.9 2009.6667 SEP 139.1 67.8 20.3 19.2 13.7 9.0 2009.7500 OCT 144.1 71.6 22.8 19.5 13.8 9.2 2009.8333 NOV 149.0 75.2 25.2 19.7 13.9 9.3 2009.9167 DEC 153.8 78.9 27.6 19.9 14.0 9.5 2010.0000 JAN 158.4 82.4 30.0 20.1 14.1 9.6 2010.0833 FEB 162.9 85.7 32.2 20.4 14.2 9.8 2010.1667 MAR 167.2 89.0 34.4 20.6 14.2 9.9 2010.2500 APR 171.3 92.0 36.5 20.7 14.3 10.0 2010.3333 MAY 175.2 95.0 38.4 20.9 14.4 10.2 2010.4167 JUN 178.8 97.7 40.2 21.1 14.5 10.3 2010.5000 JUL 182.1 100.2 41.9 21.3 14.5 10.4 2010.5833 AUG 185.1 102.4 43.4 21.4 14.6 10.5 2010.6667 SEP 187.8 104.5 44.8 21.5 14.6 10.5 2010.7500 OCT 190.1 106.2 45.9 21.6 14.7 10.6 2010.8333 NOV 192.1 107.7 46.9 21.7 14.7 10.7 2010.9167 DEC 193.7 108.9 47.7 21.8 14.7 10.7 2011.0000 JAN 194.8 109.8 48.3 21.9 14.8 10.8 2011.0833 FEB 195.5 110.3 48.7 21.9 14.8 10.8 2011.1667 MAR 195.8 110.5 48.8 21.9 14.8 10.8 2011.2500 APR 192.0 109.8 47.2 20.6 14.9 11.5 2011.3333 MAY 187.4 108.5 46.2 20.2 15.0 11.8 2011.4167 JUN 183.2 107.1 45.1 19.7 15.1 11.7 2011.5000 JUL 181.5 105.9 43.5 19.4 15.3 11.9 2011.5833 AUG 180.9 104.9 41.5 19.2 15.6 12.1 2011.6667 SEP 179.8 104.1 40.1 19.0 15.7 11.6 2011.7500 OCT 178.4 103.1 39.1 19.0 15.7 10.9 2011.8333 NOV 176.8 102.1 38.3 18.9 15.7 10.8 2011.9167 DEC 176.2 100.7 37.1 19.0 15.7 10.8 2012.0000 JAN 174.8 99.2 35.9 19.2 15.8 10.8 2012.0833 FEB 173.9 97.4 35.1 19.8 15.9 10.8 2012.1667 MAR 172.8 95.9 33.8 20.4 16.1 10.9 2012.2500 APR 169.3 94.3 32.0 21.4 16.3 10.8 2012.3333 MAY 165.6 93.1 30.8 21.9 16.5 10.7 2012.4167 JUN 162.5 92.1 30.4 21.6 16.6 10.6 2012.5000 JUL 158.1 91.3 29.1 21.3 16.4 10.3 2012.5833 AUG 156.8 90.4 27.2 21.8 16.5 10.3 2012.6667 SEP 156.5 88.9 25.5 23.1 16.7 10.4 2012.7500 OCT 152.5 87.0 24.2 23.3 16.9 10.9 2012.8333 NOV 149.4 85.0 23.3 22.7 17.0 11.7 2012.9167 DEC 150.9 83.1 22.3 22.6 17.0 11.8 2013.0000 JAN 150.5 81.4 21.1 22.7 16.9 11.9 2013.0833 FEB 148.5 79.8 19.8 23.2 17.1 12.0 2013.1667 MAR 146.8 78.6 18.3 23.9 17.3 12.1 2013.2500 APR 144.1 77.0 16.7 23.9 17.2 12.5 2013.3333 MAY 140.8 75.0 15.2 23.9 17.1 13.3 2013.4167 JUN 140.1 73.1 13.5 23.3 17.0 13.7 2013.5000 JUL 141.3 71.3 11.9 21.6 16.8 13.3 2013.5833 AUG 141.3 69.7 11.1 21.8 16.6 12.8 2013.6667 SEP 140.2 68.2 10.6 21.8 16.4 12.7 2013.7500 OCT 141.1 66.8 9.7 21.5 16.4 12.5 2013.8333 NOV 143.7 65.4 9.3 21.1 16.4 12.4 2013.9167 DEC 143.7 64.0 9.4 20.5 16.4 12.2 2014.0000 JAN 142.5 62.5 9.4 19.9 16.1 11.9 2014.0833 FEB 142.2 61.0 8.9 20.1 16.0 11.9 2014.1667 MAR 140.8 59.3 8.6 21.6 15.9 11.7 2014.2500 APR 139.4 57.6 8.2 23.2 15.8 11.7 2014.3333 MAY 139.2 56.0 8.0 24.0 15.8 11.5 2014.4167 JUN 139.0 54.3 8.5 25.1 15.7 11.3 2014.5000 JUL 137.9 52.9 9.1 25.8 15.7 11.3 2014.5833 AUG 135.6 51.7 9.5 25.0 15.6 10.8 2014.6667 SEP 132.6 50.4 9.7 25.0 15.6 10.3 2014.7500 OCT 127.7 49.2 9.3 24.1 15.7 10.7 2014.8333 NOV 120.8 47.4 8.5 22.2 15.7 10.8 2014.9167 DEC 113.1 45.5 7.7 21.4 15.6 10.8 2015.0000 JAN 106.0 43.9 7.0 21.7 15.8 11.0 2015.0833 FEB 100.7 42.6 6.2 22.4 16.0 11.2 2015.1667 MAR 96.9 41.0 5.5 22.6 16.0 11.2 2015.2500 APR 94.3 39.4 5.0 22.5 16.1 11.0 2015.3333 MAY 89.7 37.7 4.3 22.7 16.3 11.0 2015.4167 JUN 83.6 36.0 3.2 22.9 16.6 11.3 2015.5000 JUL 79.2 34.7 2.5 23.4 16.8 11.2 2015.5833 AUG 76.2 33.5 2.0 24.1 16.9 11.2 2015.6667 SEP 73.8 32.2 1.8 24.8 17.0 11.8 2015.7500 OCT 72.4 30.9 1.8 25.4 16.9 12.2 2015.8333 NOV 70.5 29.5 1.6 25.6 16.7 12.1 2015.9167 DEC 68.4 28.2 1.2 25.4 16.4 12.0 2016.0000 JAN 65.9 27.0 0.8 24.7 16.0 12.2 2016.0833 FEB 63.0 26.1 0.6 23.6 15.6 12.3 2016.1667 MAR 59.9 25.2 0.6 22.8 15.2 12.2 2016.2500 APR 56.2 24.4 0.6 22.4 14.9 11.8 2016.3333 MAY 54.1 23.8 0.5 21.9 14.6 11.2 2016.4167 JUN 52.2 23.0 0.3 21.6 14.2 10.7 2016.5000 JUL 48.8 22.0 0.2 20.9 13.8 10.0 2016.5833 AUG 45.5 20.9 0.1 20.0 13.4 9.4 2016.6667 SEP 42.3 19.9 0.0 18.7 13.1 9.0 2016.7500 OCT 39.5 18.9 0.0 18.2 12.8 8.5 2016.8333 NOV 37.6 18.1 0.0 18.7 12.6 8.0 2016.9167 DEC 36.4 17.3 0.3 18.7 12.5 7.8 2017.0000 JAN 35.3 16.7 0.8 18.4 12.4 7.4 2017.0833 FEB 34.3 15.9 1.0 18.4 12.2 7.0 2017.1667 MAR 33.1 15.1 1.3 18.8 12.1 6.6 2017.2500 APR 31.6 14.2 1.5 18.9 12.0 6.5 2017.3333 MAY 29.4 13.3 1.7 18.8 12.0 6.4 2017.4167 JUN 27.0 12.3 2.0 18.4 11.9 6.6 2017.5000 JUL 25.7 11.4 2.5 17.5 11.8 6.9 2017.5833 AUG 25.5 10.9 2.6 16.5 11.7 7.2 2017.6667 SEP 25.3 10.5 2.6 16.3 11.6 7.4 2017.7500 OCT 24.9 10.0 2.6 16.6 11.6 7.5 2017.8333 NOV 23.9 9.6 2.4 16.9 11.6 7.5 2017.9167 DEC 22.7 9.3 2.3 17.2 11.6 7.7 2018.0000 JAN 21.7 9.3 1.9 17.3 11.6 7.7 2018.0833 FEB 20.7 9.3 1.8 17.7 11.5 7.6 2018.1667 MAR 19.5 9.3 1.8 18.0 11.4 7.6 2018.2500 APR 18.5 9.5 1.8 18.2 11.4 7.6 2018.3333 MAY 17.7 9.5 1.7 18.1 11.3 7.6 2018.4167 JUN 18.3 9.6 1.7 17.8 11.2 7.5 2018.5000 JUL 19.6 10.0 2.4 17.3 11.1 7.5 2018.5833 AUG 21.2 10.7 3.0 16.3 11.0 7.5 2018.6667 SEP 23.0 11.5 3.8 15.5 10.9 7.5 2018.7500 OCT 24.7 12.3 4.0 16.1 10.8 7.7 2018.8333 NOV 26.1 13.4 4.5 16.3 10.8 7.7 2018.9167 DEC 28.3 14.8 5.2 16.6 10.9 7.8 2019.0000 JAN 31.0 16.2 5.8 16.7 11.0 7.7 2019.0833 FEB 33.9 17.8 6.2 16.8 11.1 7.7 2019.1667 MAR 37.7 19.6 7.4 17.1 11.1 7.8 2019.2500 APR 42.2 21.6 8.3 17.3 11.1 8.0 2019.3333 MAY 47.1 24.0 8.8 17.3 11.2 8.3 2019.4167 JUN 51.6 26.5 8.8 17.4 11.5 8.6 2019.5000 JUL 55.2 28.8 9.2 17.6 11.7 9.0 2019.5833 AUG 57.5 31.3 9.3 17.5 12.0 8.8 2019.6667 SEP 60.1 34.0 10.0 16.9 12.2 8.7 2019.7500 OCT 67.7 37.1 10.8 16.2 12.4 8.9 2019.8333 NOV 75.3 40.0 11.1 16.0 12.5 9.0 2019.9167 DEC 82.5 42.8 11.2 16.0 12.7 9.0 2020.0000 JAN 90.4 45.8 12.0 16.1 12.9 8.8 2020.0833 FEB 99.7 48.7 14.2 16.7 13.0 8.4 2020.1667 MAR 108.9 51.4 14.2 17.1 13.0 8.2 2020.2500 APR 117.1 54.1 14.4 17.5 13.1 8.2 2020.3333 MAY 125.4 57.2 14.8 18.2 13.2 8.1 2020.4167 JUN 134.0 60.6 15.4 18.5 13.2 7.9 2020.5000 JUL 140.4 63.7 17.0 18.5 13.1 7.8 2020.5833 AUG 143.1 66.2 18.8 18.7 13.1 7.9 2020.6667 SEP 145.6 68.4 19.7 19.0 13.2 8.1 2020.7500 OCT 149.2 70.7 21.5 18.6 13.3 8.6 2020.8333 NOV 152.7 73.2 24.0 17.8 13.3 9.2 2020.9167 DEC 157.6 75.7 26.5 18.1 13.4 9.6 2021.0000 JAN 162.1 78.4 29.1 18.9 13.5 10.1 2021.0833 FEB 164.3 81.0 30.9 19.1 13.6 10.1 2021.1667 MAR 168.2 83.9 32.1 19.5 13.9 10.3 2021.2500 APR 174.2 87.3 34.4 20.5 14.1 10.4 2021.3333 MAY 178.1 90.5 36.7 20.2 14.1 10.6 2021.4167 JUN 180.7 93.2 38.2 20.4 14.1 10.2 2021.5000 JUL 184.1 96.0 40.9 20.7 14.1 10.2 2021.5833 AUG 187.5 99.0 43.9 21.1 14.2 9.9 2021.6667 SEP 190.8 101.8 45.9 21.4 14.2 9.8 2021.7500 OCT 193.0 104.2 47.3 21.4 14.4 10.5 2021.8333 NOV 194.0 106.2 47.5 21.6 14.5 10.9 2021.9167 DEC 193.3 108.2 46.7 21.9 14.7 10.9 2022.0000 JAN 192.9 110.4 46.3 22.4 14.9 11.0 2022.0833 FEB 195.2 112.7 47.8 22.9 15.1 11.2