Statistics on worldwide searches (impressions)

Hello.
I’m looking for statistics about number of searches worldwide, and not just in the US:
-Distribution between search engines (how much percents for Google etc).
-Number of impressions (unique visitors) per search engine and/or per country.
Data period : 2006 and/or January 2007
For example, here’s a link with statistics in USA only:
http://www.clickz.com/showPage.html?page=3625080
Thanks

Original post by Natively