Sunspot numbers obtained by different networks in 1999 ====================================================== SIDC SONNE SONNE AAVSO AKS BAA GFOES GSI OAA RWG TOS VVS prov. prov. def. prov. (D) (GB) (F) (I) (J) (CH) (PL) (B) Jan 62.4 59.7 55.8 70.9 80.7 62.8 56.4 69.1 64.8 61.6 61.1 69.1 Feb 66.1 64.2 63.9 79.0 65.5 69.8 62.8 72.2 74.7 73.7 67.0 83.4 Mar 69.1 65.8 66.4 79.8 56.1 73.9 65.0 117.0 73.4 72.9 78.7 80.1 Apr 63.9 63.9 62.7 78.6 60.1 62.1 68.2 69.3 68.7 68.0 67.3 82.2 May 106.3 99.0 98.1 119.0 97.8 105.6 102.9 103.3 109.4 113.2 110.9 124.2 Jun 137.4 133.1 133.8 164.7 198.1 145.1 132.9 163.4 158.1 156.5 145.6 163.7 Jul 113.5 119.8 115.9 141.8 116. 130.1 118.3 133.2 132.4 136.9 129.1 138.7 Aug 93.7 91.2 91.4 110.8 95.3 96.1 89.3 - 105.0 102.6 103.2 114.8 Sep 70.9 74.1 73.1 87.7 70. 74.9 76.6 - 77.3 78.6 87.5 83.6 Oct 116.4 114.7 112.0 141.7 116.5 120.5 117.1 - 126.7 123.5 129.6 149.2 Nov 132.7 129.3 128.5 167.6 116.6 136.4 125.2 176.1 150.3 157.3 134.9 173.4 Dec 86.4 72.7 75.3 101.8 69.7 88.1 81.2 77.3 95.8 82.7 89.5 98.1 SIDC: Sunspot Index Data Center, Brussels (International sunspot numbers) SONNE prov.: SONNE network, provisional sunspot numbers SONNE def.: SONNE network, definitive sunspot numbers AAVSO: American Association of Variable Star Observers - Solar Division AKS: Arbeitskreis Sonne des Kulturbundes e.V., Germany BAA: The British Astronomical Association - Solar Section, UK GFOES: G.F.O.E.S. Commission "Nombre de Wolf", France GSI: Gruppo Sole Italia, Italy OAA: The Oriental Astronomical Association - Solar Division, Japan RWG: Rudolf Wolf Gesellschaft - Solar Obs. Group of Swiss Astron. Society TOS: Towarzystwo Obserwatorow Slonca - Solar Observers Society, Poland VVS: Vereniging voor Sterrenkunde, Werkgroep Zon, Belgium