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% 1999.5840 AUG 100.7 96.4 93.1 13.1 12.8 12.3 1999.6673 SEP 109.2 98.7 92.9 13.9 12.9 12.1 1999.7507 OCT 117.1 100.7 91.9 14.9 13.0 11.6 1999.8340 NOV 122.5 101.9 89.8 15.2 13.2 11.3 1999.9173 DEC 129.2 102.8 87.1 15.5 13.5 11.3 2000.0007 JAN 133.7 103.0 84.7 16.4 13.8 11.5 2000.0840 FEB 137.2 103.3 81.4 16.7 14.2 11.8 2000.1673 MAR 140.6 104.1 78.0 16.9 14.5 11.5 2000.2507 APR 143.7 104.8 75.1 16.9 14.6 11.2 2000.3340 MAY 148.5 105.3 73.2 17.2 14.6 10.8 2000.4173 JUN 149.3 104.7 72.6 17.8 14.7 10.6 2000.5007 JUL 145.1 103.3 72.4 18.5 14.8 10.2 2000.5840 AUG 140.9 102.0 70.3 18.7 14.9 9.8 2000.6673 SEP 140.1 101.1 67.3 18.4 14.8 9.0 2000.7507 OCT 141.3 100.9 66.6 17.9 14.6 8.4 2000.8340 NOV 141.7 100.6 67.0 18.2 14.6 8.3 2000.9173 DEC 141.5 100.0 66.7 18.6 14.6 8.3 2001.0007 JAN 140.3 99.4 67.4 19.3 14.5 7.9 2001.0840 FEB 138.0 98.8 64.7 19.3 14.2 7.6 2001.1673 MAR 133.9 98.3 60.7 18.7 14.0 7.8 2001.2507 APR 128.6 97.6 58.4 18.5 14.0 8.3 2001.3340 MAY 125.4 96.8 56.7 18.3 14.0 8.7 2001.4173 JUN 122.3 95.7 55.2 17.9 13.9 9.0 2001.5007 JUL 118.3 94.5 53.9 17.9 13.9 9.2 2001.5840 AUG 116.0 92.7 51.4 17.6 13.9 9.3 2001.6673 SEP 116.3 91.0 49.7 17.2 14.1 9.5 2001.7507 OCT 116.1 89.6 48.4 17.5 14.5 10.3 2001.8340 NOV 115.6 88.4 47.6 17.7 14.5 10.7 2001.9173 DEC 115.1 87.0 47.0 17.4 14.3 10.4 2002.0007 JAN 116.7 85.3 46.9 18.2 14.4 10.8 2002.0840 FEB 119.3 83.7 46.6 19.6 14.8 11.2 2002.1673 MAR 120.1 82.5 45.6 20.8 15.1 11.4 2002.2507 APR 118.4 81.2 44.4 21.4 15.3 11.6 2002.3340 MAY 117.3 79.6 42.5 22.5 15.5 11.7 2002.4173 JUN 117.0 77.8 39.1 22.9 15.7 11.4 2002.5007 JUL 115.1 76.1 36.2 22.3 15.8 11.5 2002.5840 AUG 112.4 74.7 35.0 22.3 15.7 11.4 2002.6673 SEP 109.1 73.5 35.0 21.6 15.7 11.2 2002.7507 OCT 105.4 72.3 35.1 19.8 15.7 11.1 2002.8340 NOV 102.7 70.9 34.3 18.9 15.7 11.1 2002.9173 DEC 101.3 69.2 33.1 19.9 15.9 11.2 2003.0007 JAN 98.4 67.3 31.2 20.1 15.9 11.4 2003.0840 FEB 93.3 65.3 29.5 19.9 15.8 11.2 2003.1673 MAR 88.3 62.9 28.5 19.8 15.6 11.2 2003.2507 APR 86.4 60.7 28.1 19.2 15.5 11.3 2003.3340 MAY 84.0 58.9 25.9 19.5 15.7 11.4 2003.4173 JUN 83.1 57.4 25.1 20.2 15.9 11.5 2003.5007 JUL 82.0 55.9 24.6 20.2 16.1 11.5 2003.5840 AUG 80.6 54.3 23.6 20.0 16.3 11.4 2003.6673 SEP 80.2 52.6 21.5 19.9 16.4 11.3 2003.7507 OCT 80.2 50.9 18.3 19.7 16.4 11.0 2003.8340 NOV 79.6 49.2 16.3 19.8 16.4 11.0 2003.9173 DEC 77.1 47.3 15.1 20.3 16.4 11.2 2004.0007 JAN 76.1 45.6 13.6 20.8 16.5 11.8 2004.0840 FEB 74.9 44.3 12.4 21.0 16.8 12.3 2004.1673 MAR 72.4 43.1 11.6 20.6 17.0 12.4 2004.2507 APR 70.0 42.0 11.3 21.1 17.0 12.4 2004.3340 MAY 68.5 40.6 10.4 22.0 16.9 12.4 2004.4173 JUN 67.8 39.1 9.2 22.3 16.7 12.5 2004.5007 JUL 66.5 37.6 8.5 22.1 16.6 13.3 2004.5840 AUG 63.8 36.2 7.9 21.7 16.7 12.7 2004.6673 SEP 60.3 34.8 7.9 22.0 16.9 12.5 2004.7507 OCT 57.0 33.4 8.2 21.7 16.8 12.2 2004.8340 NOV 53.9 32.2 8.5 21.6 16.6 11.7 2004.9173 DEC 52.7 31.4 8.4 21.7 16.3 11.3 2005.0007 JAN 51.3 30.4 8.3 21.7 15.9 10.7 2005.0840 FEB 50.0 29.1 8.8 22.1 15.6 9.5 2005.1673 MAR 47.9 27.6 8.8 22.4 15.3 8.4 2005.2507 APR 45.4 26.4 7.9 22.7 15.2 8.1 2005.3340 MAY 44.6 25.5 8.0 22.9 15.2 7.9 2005.4173 JUN 42.9 24.5 8.0 23.1 15.1 7.7 2005.5007 JUL 40.5 23.6 7.7 22.8 15.0 7.7 2005.5840 AUG 39.6 22.6 7.3 22.3 14.9 7.9 2005.6673 SEP 39.0 21.7 7.0 21.5 14.7 8.3 2005.7507 OCT 37.0 20.5 6.5 20.8 14.6 8.7 2005.8340 NOV 35.0 19.3 5.9 20.6 14.7 8.9 2005.9173 DEC 33.0 18.2 5.4 20.4 14.9 9.0 2006.0007 JAN 31.1 17.0 4.9 20.4 15.2 9.5 2006.0840 FEB 29.2 15.9 4.4 20.2 15.3 10.0 2006.1673 MAR 27.3 14.8 3.9 19.9 15.3 10.3 2006.2507 APR 25.5 13.8 3.5 20.1 15.2 10.6 2006.3340 MAY 23.8 12.8 3.0 20.2 15.0 11.1 2006.4173 JUN 22.2 11.8 2.6 20.3 14.8 11.8 2006.5007 JUL 20.6 10.9 2.2 19.9 14.7 11.7 2006.5840 AUG 19.2 10.0 1.8 19.5 14.6 11.6 2006.6673 SEP 17.8 9.2 1.5 18.9 14.6 11.4 2006.7507 OCT 16.6 8.5 1.1 18.1 14.7 11.1 2006.8340 NOV 15.5 7.9 0.9 18.0 14.7 10.4 2006.9173 DEC 14.6 7.3 0.6 17.9 14.5 10.2 2007.0007 JAN 13.8 6.9 0.4 17.8 14.4 10.1 2007.0840 FEB 13.1 6.5 0.2 17.4 14.3 10.1 2007.1673 MAR 12.7 6.2 0.1 17.1 14.3 10.2 2007.2507 APR 12.4 6.0 0.0 16.6 13.8 9.9 2007.3340 MAY 12.3 6.0 0.0 16.0 13.3 9.6 2007.4173 JUN 12.9 6.3 0.4 15.5 12.9 9.3 2007.5007 JUL 14.3 6.9 0.7 15.0 12.4 9.1 2007.5840 AUG 15.5 7.6 1.0 14.5 12.0 8.8 2007.6673 SEP 16.7 8.2 1.5 14.0 11.6 8.5 2007.7507 OCT 18.1 9.0 1.7 13.6 11.2 8.3 2007.8340 NOV 20.6 9.9 2.2 13.2 10.8 8.0 2007.9173 DEC 22.9 10.9 2.7 12.8 10.5 7.8 2008.0007 JAN 25.0 12.0 2.9 12.4 10.1 7.6 2008.0840 FEB 28.3 13.2 3.1 12.1 9.9 7.5 2008.1673 MAR 32.2 14.6 3.3 11.8 9.6 7.3 2008.2507 APR 38.3 16.3 3.3 11.5 9.4 7.2 2008.3340 MAY 43.7 18.3 3.3 11.4 9.2 7.1 2008.4173 JUN 47.9 20.4 4.0 11.2 9.1 7.0 2008.5007 JUL 53.9 22.6 4.2 11.1 9.0 6.9 2008.5840 AUG 60.9 25.0 4.3 11.1 9.0 6.9 2008.6673 SEP 67.5 27.6 4.8 11.3 9.1 6.9 2008.7507 OCT 75.1 30.2 4.6 11.6 9.3 7.1 2008.8340 NOV 83.9 33.0 4.8 11.7 9.4 7.4 2008.9173 DEC 90.9 36.2 5.6 11.9 9.5 7.5 2009.0007 JAN 96.0 39.9 6.6 12.0 9.6 7.5 2009.0840 FEB 100.8 43.5 7.3 12.1 9.6 7.3 2009.1673 MAR 105.5 46.9 8.6 12.2 9.7 7.2 2009.2507 APR 110.7 50.3 9.5 12.6 9.8 7.0 2009.3340 MAY 116.4 53.7 9.6 12.9 10.1 6.9 2009.4173 JUN 121.8 57.4 11.1 13.3 10.5 7.1 2009.5007 JUL 126.2 61.0 12.2 13.8 10.8 7.5 2009.5840 AUG 134.2 64.5 13.2 14.6 11.1 7.8 2009.6673 SEP 141.9 67.7 14.4 15.8 11.4 7.6 2009.7507 OCT 146.6 71.2 14.9 16.2 11.6 7.6 2009.8340 NOV 148.6 74.6 15.4 16.4 11.7 7.5 2009.9173 DEC 151.8 77.4 16.0 16.9 11.9 7.5 2010.0007 JAN 155.5 79.8 16.4 18.1 12.2 7.5 2010.0840 FEB 159.3 81.9 16.7 19.0 12.6 7.6 2010.1673 MAR 164.8 84.2 16.6 19.2 12.8 7.6 2010.2507 APR 168.2 86.5 16.1 19.3 13.0 7.7 2010.3340 MAY 169.9 88.9 15.7 19.1 13.2 7.6 2010.4173 JUN 173.9 91.1 16.1 18.7 13.3 7.6 2010.5007 JUL 178.8 93.2 16.6 18.6 13.3 7.7 2010.5840 AUG 181.8 95.2 17.7 19.0 13.5 7.9 2010.6673 SEP 183.9 97.4 19.5 18.9 13.6 8.1 2010.7507 OCT 186.7 99.4 20.7 17.9 13.6 8.5 2010.8340 NOV 189.2 100.7 22.0 18.0 13.8 8.6 2010.9173 DEC 191.5 101.6 24.3 18.6 14.1 8.6 2011.0007 JAN 192.9 101.8 27.0 19.2 14.3 8.9 2011.0840 FEB 194.3 102.2 29.8 19.7 14.8 9.3 2011.1673 MAR 194.4 103.0 31.5 20.4 15.1 9.5 2011.2507 APR 193.8 103.6 32.8 20.4 15.2 9.5 2011.3340 MAY 195.2 104.2 35.3 20.4 15.2 9.7 2011.4173 JUN 195.8 103.7 37.1 20.6 15.2 9.9 2011.5007 JUL 192.6 102.3 39.5 20.9 15.4 10.4 2011.5840 AUG 188.0 101.0 41.2 21.3 15.4 11.0 2011.6673 SEP 183.4 100.2 41.9 21.3 15.3 11.6 2011.7507 OCT 181.2 100.0 43.4 21.5 15.1 11.2 2011.8340 NOV 180.5 99.8 43.7 21.7 15.1 11.1 2011.9173 DEC 179.4 99.1 43.2 22.1 15.1 10.6 2012.0007 JAN 178.2 98.5 43.3 22.9 15.0 10.1 2012.0840 FEB 176.8 98.0 45.1 22.6 14.7 9.8 2012.1673 MAR 176.1 97.4 46.0 21.4 14.4 10.0 2012.2507 APR 175.0 96.8 45.4 20.7 14.3 10.0 2012.3340 MAY 173.8 95.9 44.6 20.1 14.2 10.2 2012.4173 JUN 172.1 94.9 44.5 19.7 14.1 10.5 2012.5007 JUL 169.5 93.7 45.1 19.6 14.1 10.5 2012.5840 AUG 165.3 92.0 44.1 19.4 14.1 10.4 2012.6673 SEP 162.0 90.2 43.4 19.2 14.4 10.4 2012.7507 OCT 158.7 88.8 44.4 19.0 14.7 10.4 2012.8340 NOV 154.4 87.7 45.5 19.0 14.9 10.2 2012.9173 DEC 150.8 86.3 44.5 19.5 14.8 9.8 2013.0007 JAN 146.5 84.6 42.5 20.5 14.9 10.1 2013.0840 FEB 142.9 83.1 41.6 22.1 15.3 10.6 2013.1673 MAR 142.2 81.9 41.3 23.5 15.6 10.6 2013.2507 APR 138.9 80.6 39.2 24.1 15.8 10.8 2013.3340 MAY 136.8 79.1 34.9 25.3 16.1 10.9 2013.4173 JUN 135.9 77.3 33.9 25.8 16.3 11.1 2013.5007 JUL 132.9 75.6 35.4 25.0 16.3 11.4 2013.5840 AUG 129.3 74.2 34.8 24.9 16.2 11.6 2013.6673 SEP 125.3 73.1 33.1 24.1 16.2 11.7 2013.7507 OCT 121.0 71.9 31.9 22.2 16.1 11.7 2013.8340 NOV 117.5 70.5 31.3 22.5 16.2 11.9 2013.9173 DEC 115.3 68.8 30.2 23.2 16.3 11.7 2014.0007 JAN 111.4 66.9 28.4 23.3 16.3 10.9 2014.0840 FEB 104.9 64.9 27.0 22.8 16.1 10.6 2014.1673 MAR 98.0 62.6 26.2 22.1 15.9 10.7 2014.2507 APR 94.1 60.4 26.3 22.0 15.9 10.7 2014.3340 MAY 93.1 58.6 25.8 22.9 16.1 10.6 2014.4173 JUN 92.2 57.1 24.2 23.8 16.4 10.7 2014.5007 JUL 89.9 55.6 24.3 24.0 16.6 10.7 2014.5840 AUG 87.6 54.1 23.9 24.0 16.8 10.6 2014.6673 SEP 83.8 52.4 22.9 24.0 16.9 10.5 2014.7507 OCT 80.3 50.7 22.1 23.6 16.9 10.2 2014.8340 NOV 76.6 49.0 20.9 22.7 16.9 10.3 2014.9173 DEC 71.1 47.1 19.3 22.9 16.8 10.5 2015.0007 JAN 69.8 45.4 16.8 23.1 16.9 11.3 2015.0840 FEB 70.3 44.2 14.9 23.2 17.2 11.8 2015.1673 MAR 69.9 42.9 13.8 22.6 17.3 11.9 2015.2507 APR 69.7 41.8 12.3 21.6 17.2 12.1 2015.3340 MAY 68.9 40.4 10.5 21.3 17.1 12.2 2015.4173 JUN 66.9 38.9 9.5 21.8 16.9 12.4 2015.5007 JUL 64.3 37.4 8.7 21.8 16.7 13.2 2015.5840 AUG 61.0 36.1 7.8 22.2 16.8 13.0 2015.6673 SEP 56.5 34.7 7.6 22.6 16.9 12.7 2015.7507 OCT 52.1 33.2 7.7 22.4 16.9 13.0 2015.8340 NOV 48.9 32.1 7.4 22.4 16.7 12.7 2015.9173 DEC 49.9 31.3 7.2 22.8 16.5 12.4 2016.0007 JAN 49.1 30.3 7.3 23.0 16.1 12.0 2016.0840 FEB 46.6 29.0 7.2 23.6 15.8 11.1 2016.1673 MAR 44.5 27.6 7.7 24.2 15.6 10.4 2016.2507 APR 42.4 26.3 6.6 25.0 15.5 10.5 2016.3340 MAY 41.1 25.4 6.2 25.5 15.5 10.6 2016.4173 JUN 39.5 24.4 5.8 25.7 15.5 10.5 2016.5007 JUL 38.9 23.5 5.4 25.6 15.4 10.6 2016.5840 AUG 38.3 22.5 4.9 25.0 15.3 10.9 2016.6673 SEP 37.9 21.6 4.3 24.1 15.1 11.0 2016.7507 OCT 37.1 20.6 3.5 23.1 14.9 11.2 2016.8340 NOV 36.1 19.7 3.4 22.6 15.0 11.1 2016.9173 DEC 34.9 19.0 3.3 22.2 15.2 11.0 2017.0007 JAN 33.5 18.1 3.1 21.9 15.4 11.1 2017.0840 FEB 31.8 17.1 2.5 21.5 15.5 11.3 2017.1673 MAR 29.9 16.2 1.9 20.8 15.5 11.4 2017.2507 APR 27.1 15.3 1.4 20.0 15.3 11.4 2017.3340 MAY 24.6 14.3 1.4 20.1 15.1 11.7 2017.4173 JUN 22.2 13.1 1.2 20.2 14.9 11.9 2017.5007 JUL 20.3 12.0 0.8 19.9 14.7 11.6 2017.5840 AUG 19.2 11.1 0.5 19.5 14.6 11.5 2017.6673 SEP 19.0 10.3 0.4 19.0 14.6 11.1 2017.7507 OCT 18.6 9.5 0.4 18.2 14.6 10.6 2017.8340 NOV 18.2 8.8 0.3 17.3 14.5 9.8 2017.9173 DEC 16.8 8.3 0.2 17.4 14.4 9.4 2018.0007 JAN 15.9 7.8 0.1 17.5 14.3 9.3 2018.0840 FEB 15.9 7.3 0.0 17.6 14.2 9.3 2018.1673 MAR 15.1 6.8 0.0 17.6 14.1 9.3