Opps. Doing a little fuzzy math here.
http://www.csis.org/europe/frm990412.html Here is where an estimate of the Muslim population in France. Which is 4-5 million according to them. There are other sources that put it at or near the 6 million mark.
http://www.factbook.net/muslim_pop.php According to these sites, the percentages is around 10% (instead of the 15% I said before [though I seem to remember getting that number before. Hmmmmm. Maybe there is another number floating around]) since France has a population of 60 million.
Still, even 10% is a LOT of Muslims in a supposively "Christian" nation.
I was surprised to see that Germany has only 2.9 million muslims.