3.23, a fall of 1.94 children per woman, or 38%. While Muslims have an average of 3.1 children per woman—the highest rate of all religious groups—Christians are second, with 2.7 children per woman. The gap in fertility between the Christian- and Muslim-dominated nations fell from 67% in 1990 to 17% in 2010. According to a study published by the Pew Research Center in 2017, births to Muslims between the years of 2010 and 2015 made up an estimated 31% of all babies born around the world. By the Pew Research Center's estimates, the Muslim fertility rate and Christian fertility rate will converge by 2040. Conversion According to the World Christian Encyclopedia, approximately 2.7 million convert to Christianity annually from another religion; World Christian Encyclopedia also stated that Christianity ranks in first place in net gains through religious conversion. While, according to book "The Oxford Handbook of Religious Conversion", which published by the professor of Christian mission Charles E. Farhadian, and the professor of psychology Lewis Ray Rambo, between 1990 and 2000, approximately 1.9 million people converted to Christianity from another religion, with Christianity ranking first in net gains through religious conversion. According to "The Oxford Handbook of Religious Conversion", in mid-2005 approximately 15.5 million converted to Christianity from another religion, approximately 11.7 million left Christianity, and most of them became irreligious, resulting in a net gain of 3.8 million. Christianity added about 65.1 million people due to factors such as birth rate and religious conversion, while it lost 27.4 million people due to factors such as death rate and religious apostasy in mid-2005. Most of the net growth in the numbers of Christians is in Africa, Latin America and Asia. Christianity is expected to lose a net of 66 million adherents (40 million converts versus 106 million apostate) mostly to religiously unaffiliated category between 2010 and 2050, it is also expected that Christianity may have the largest net loses in terms of religious conversion. However, these forecasts lack reliable data on religious conversion in China, but according to media reports and expert assessments, it is possible that the rapid growth of Christianity in China may maintain, or even increase, the current numerical advantage of Christianity as the largest religion in the world. This scenario (Chinese scenario) is based primarily on sensitivity tests. According to scholar Philip Jenkins Christianity is growing rapidly in China and some other Asian countries and sub-Saharan