i really doubt linux is that high, allow me to explain

the w3c site says
From the statistics below, collected from W3Schools' log-files over a period of five years...
linux tends to be used by people who know computers really well, or at least above average computer usage knowledge. they may know html, know of it and wish to know more, or looking around and stopped by the site as it's on a tech thing, html and such...
for other stats sites they go off of the toolbars.. counters

not trying to be pessimistic... but the teriible thing on OS stats is it very hard to get the right numbers on everyone