Real search engine usage stats per country?

Most yahoo/google stats are just user popularity, which doesn't really help in knowing how much people DO NOT use google for searches.

Are there are reliable stats, just based on something like a poll of random people, as to who they use for a search engine - per country?

I'm interested in Canada, US, UK, Aussie and NZ.

I don't know a sole who does not use google for searches, not one. So I'm having a hard time caring about stats that show YAHOO has even 10% of searches.

Sources, ideas ?

THe reason I ask is this: I am going to laucn an AdWords campaign - but don't know if I should bother, right now with limited funds before getting investors, with also launching Yahoo/overture campaigns as well - or just screw it.

Thanks!