Assalamu 3alaykom !
I think the best way to do this is by voting because it's more representative and more interactive; but as this thread is not visible by many members, the following numbers may help. But the best results could be made by voting (many members with religion "undisclosed" can vote for their religion anonymously).
I collected these numbers today (4, 17, 2010 at 12:31 am), I used the "member list" feature in the forum :
Community->Member List ->Search Members -> Advanced Search -> religion (member list by religion)
religion.........number..... %
Undisclosed....... 1371.........15.68...[][][][][][][][][]
Muslim..............6676.........76.38... [][][][][][][][][][][][][][][][][][][][][][][][][][][]
Christian...........321...........3.67.....[][][][]
Atheist..............128...........1.46....[][]
Agnostic............84............0.96.....[]
Bahai ................7..............0.08
Bddhist..............19............0.22
Confucian..........2..............0.02
Hindu................16............0.18
Jainist...............2..............0.02
Jedi..................20.............0.23
Jewish..............16.............0.18
Judeo-Christian..5..............0.06
Pagan...............11.............0.13
Sabian..............3.............. 0.03
Shinto...............0..............0.00
Sikh..................20............ 0.23
Taoist...............2.............. 0.02
Wiccan..............4..............0.05
Zoroastrian........3..............0.03
Other................31.............0.35....[]
Total.................8741.........100.00
Data sheet (.xls) ..
These numbers are still not accurate because there is a big part of members with religion "Undisclosed", and because new members are still joining the forum so the numbers may change.
As I said, the best results can be obtained if all the members in the forum vote, but that's a little bit difficult.