Here is a table which shows what percentage of browsers are being used to access the web
for a particular time period:

4. Operating Systems

% Visits from OS	11/1/09 - 2/1/10	11/1/10 - 2/1/11	Difference
Windows	89.9%	84.8%	-5.1%
Macintosh	4.5%	5.2%	+0.7%
Linux	0.6%	0.7%	+0.1%
Other	5%	9.3%	+4.3%

Dave