It's better to optimize the text written in french without the accents or with them? By example in body text should I use "Notre activité est..." or "Notre activite est..." ?

Where cand I find information about how many searches are done using accent or not? How french are searching for? With or without accents and special caracters?

I think the question is also available for other languages that are using special charachters.

Take a look at this thread :
http://forums.searchenginewatch.com/showthread.php?t=6013&page=1