The revision is well documented in a 80-pages paper (Clette et al., 2014; Clette F., Svalgaard L., Vaquero J.M., Cliver E.W: Revisiting the Sunspot Number . arxiv.org/ftp/arxiv/papers/1407/1407.3231.pdf) and effectively divergence between SN and GN appears to be reduced.
Anything in the paper is well documented, but I'm sure that the Monks who
corrected older manuscript while copying them, have similar convincing
reasons (at least at their own eyes...) like faith, Holy Bible, Aristotelic
prescriptions, Ptolemaic system of celestial spheres, etc.
For these reasons I saved here the original files, actually (June 27, 2015) available at WDC-SILSO.
The new revised data on sunspot number are available at
http://www.sidc.be/silso/datafiles. [Credits: SILSO data/image, Royal
Observatory of Belgium, Brussels]
SILSO images and data can be freely downloaded as public data. However, any public use, web based or paper publication of those data must include an explicit credit to the source: (SILSO data/image, Royal Observatory of Belgium, Brussels)