Whats the number of Muslims in Russia?

There are between 7 and 9 million people who practise Islam in Russia, and that the rest are only Muslims by ethnicity. Muslim communities are concentrated among the various minority nationalities residing between the Black Sea and the Caspian Sea: Adyghe, Balkars, Chechens, Circassians, Ingush, Kabardin, Karachay, and numerous Dagestani peoples. [Source: Wikipedia]