From the SIDC (World Data Center for the Sunspot Index):
Provisional International Sunspot Numbers
Provisional International monthly mean Sunspot Number for
April 2013 : 72.4 (seventy-two point four)
Maximum : 101 on 30 // Minimum : 53 on 1
Provisional daily International Sunspot Numbers for April 2013 :
1.. 53 6.. 76 11.. 85 16.. 63 21.. 63 26.. 71
2.. 66 7.. 85 12.. 84 17.. 64 22.. 60 27.. 72
3.. 68 8.. 82 13.. 79 18.. 57 23.. 55 28.. 69
4.. 63 9.. 92 14.. 74 19.. 59 24.. 66 29.. 95
5.. 77 10.. 94 15.. 63 20.. 61 25.. 75 30..101
70 cooperating stations on May 1, 10 UT
Predictions of the monthly smoothed Sunspot Number using the last
provisional value, calculated for October 2012 : 58.6 (+-5%)
SM CM SM CM SM CM
2012 Nov 57 60 2013 May 48 75 2013 Nov 43 90
Dec 56 64 Jun 47 78 Dec 43 88
2013 Jan 54 67 Jul 46 81 2014 Jan 42 87
Feb 52 70 Aug 45 83 Feb 41 86
Mar 50 72 Sep 45 86 Mar 41 85
Apr 49 74 Oct 44 89 Apr 40 84
SM : SIDC classical method : based on an interpolation of Waldmeier's
standard curves; the estimated error ranges from 7% (first month) to
35% (last month)
CM : Combined method : the combined method is a regression technique
coupling a dynamo-based estimator with Waldmeier's idea of standard
curves, due to K. Denkmayr.
ref. : K. Denkmayr, P. Cugnon, 1997 : "About Sunspot Number Medium-Term
Predictions", in "Solar-Terrestrial Prediction Workshop V", eds.
G. Heckman et al., Hiraiso Solar Terrestrial Research Center, Japan, 103