—In AD100 there were 181 million people in the world, to be won by 500,000 believers (that is 360 to one!)
—By 1900 there were 1 billion who did not claim to be Christians, to be evangelized by 40 million Bible-believing Christians—(that’s only 27 to one!)
—Today there are 3.4 billion non-Christians, to be evangelized by 500 million Biblebelieving Christians—That’s only 7 to one!

http://www.adopt-a-people.org/articles/world_evangelism.pdf