" The composite growth rate of 47 countries (where Islam is a majority) is 2.00%. Based 2.00% growth rate of Muslim population v/s 1.3% for the world it will take only 125 years for Muslims to be 50 % of the world population!!!! Therefore if these growth rates continue, mathematically it is a certainty that the world will be muslimised between 125 and 410 years. "

see,

http://www.faithfreedom.org/Articles/Desai/islamization_of_the_world.htm