643 positive tests covered up between 2012 and 2015. At a minimum, because of the inability to access all the relevant information from the Russians those 643 are just those known about. Russian ministers in their Sports Ministry (including those who've threatened to sue foreign press for claiming doping happened) decided whether to let a positive test stand or whether to make it disappear. Covers every sport, although athletics and weightlifting made up roughly half of the known 643 positive tests.
Scale of it is quite amazing.