I've heard numbers higher than that for China, significantly higher, from people who are involved on the ground there. Of course with the persecution that takes place there, solid numbers are hard to come by. But even your number of 100 million is more than I think you'd find in the U.S. who seriously consider themselves Christian (not those people who think they're Christian because they are born in America or such).
I'm not so sure you should believe those newsletters you still get from Liberty U, Bob. Nice to see you so enamored with China like a typical conservative. I wonder if these gazillion Christians you've apparently found over there manage to avoid the brutal one child policy of that country you so admire.