Browsers?

Would anyone who is reading this blog please let me know (in the next two days) if you are my 18% of users still using IE 6, or my 11% of users using IE 5.01? I'm in the process of making a huge overhaul of the website, and initial testing of the new design with IE5 (for mac) and IE6 (for windows under WINE) have not been promising at all. Before I go to the trouble of putting together a stripped down style sheet and style sheet switching to accommodate Microsoft's non-standard old browsers, I'd like to know if it's really necessary.

Thanks.

-JRS