This is conclusion that Todd Johnson drew in compiling an atlas recently. See his entire article, along with lot of other stats, at…

http://www.ijfm.org/PDFs_IJFM/27_4_PDFs/johnson_27_4.pdf

The truth is that Muslims, Hindus, and Buddhists are increasingly found living in ‘Christian’ lands but, apparently, increasing access has not generated closer relationships. How will they hear unless someone tells them… and how will anyone ever tell them without befriending them? In the above article, Todd Johnson asserts that, “While missionaries will always be at the forefront of innovative strategies, the whole church needs to participate in inviting people of other faiths to consider Jesus Christ.” For this reason, it seems to me that we need many more missionaries to care as much about mobilizing the church as they do about reaching the lost. Contrary to what might be popular opinion, a ministry focused on alerting the church to the needs of the unreached should be viewed as a very high priority. Somehow, we have to get the whole church to care about unreached people around the whole world. Interestingly, Johnson finishes the above article by arguing that “our de facto lack of contact with Muslims, Hindus, and Buddhists limits the fullness of our own Christian experience.” If this assertion is true, today’s average Christian is living in a sheltered world — and this “hunkering down” affects not only the growth of Christianity, but the essence of faith itself.