All we know is Apple are at less than 5.4%.
View attachment 267368
http://www.gartner.com/it/page.jsp?id=1519417
A bit of googling found that Apple sold 12.8 million computers in the four quarters ending June 2010; the number for the four quarters of 2010 would be a bit higher. The 12.8 million would have been 3.6% according to your chart, not taking into account growth since June 2010.