I know about w3schools statistics, but it much differs from the one on my company's site.
The w3schools statistics are not very representative as they only measure accesses to their site. In that case it is no surprise that your company's site has different statistics from that. It all depends on the intended audience and the usage shares in that audience. You'll get widely varying results for different sites, always. That's why useful statistics measure over many different ones.
As David Johnstone pointed out, the Wikipedia article is a good start.
It all depends on the content and the audience.
On a tech blog about Web Technologies expect a breakdown like:
Firefox: 65%
Internet Explorer: 19%
Chrome: 8%
Safari: 5%
Opera: 2%
Other: 1%
But if you are selling yarn to the local knitting community expect a breakdown like:
Internet Explorer: 88%
Firefox: 6%
Safari: 3%
Chrome: 2%
Opera: 1%
Other: 1%
Your best bet is to add Google Analytics to your site and track what stats reflect your audience.
Keep in mind that if your site is broken in any given browser - expect that percentage to drop... not because there is no audience but because they can't access your content.
Also note that time-of-day matters too. Many visitors are forced to use browser X (typically IE6 or IE7) at work - but at home they use the browser of their choice.
Since most questions about browser stats are to determine if you need to (add/remove) support for browser X, is there a browser in particular that you want more data on? e.g. cough, cough IE6?