[familyop]

The World Factbook (accessed 23SEP13)
Central Intelligence Agency
"Russia...
Religions:

Russian Orthodox 15-20%, Muslim 10-15%, other Christian 2% (2006 est.) note: estimates are of practicing worshipers; Russia has large populations of non-practicing believers and non-believers, a legacy of over seven decades of Soviet rule"

[Bold for emphasis by familyop.]

[knarf]

The wikki report used did not identify a survey group, but did state it was in 2012

"In August 2012 the first-ever sociological survey and mapping of religious adherents in Russia based on self-identification was published, with data on 79 out of 83 of the federal subjects of Russia.[1][6][7] Out of a population of 142,800,000 the survey found that 58,800,000 or 41% are Russian Orthodox, 9,400,000 or 6.5% are Muslims (including Sunni Islam, Shia Islam, and a majority of unaffiliated Muslims), 5,900,000 or 4.1% are unaffiliated Christians, 2,100,000 or 1.5% adhere to other Orthodox Churches (including Ukrainian, Georgian, Armenian and other churches)

I've got to go out ... but I'll chase down further the source(s),