Where does that number come from? I think our modern culture would look a lot different if this was true. For example, I wouldn't have to consider the following to be a subversive statement:
I heard this given in a speech by a investment professional in 2002. He went on to say that 42% of all mutual funds are held by people who define themselves as Christian. I do not know the source of his data and as such, probably shouldn't have quoted it.