According to 2012 Pew Research Center survey if current trends continue, Christianity will remains the world's largest religion by year 2050. By 2050, the Christian population is expected to exceed 3 billion. 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. High birth rates and conversion were cited as the reason for the Christian population growths. A 2015 study found that approximately 10.2 million Muslim converted to Christianity. Christianity is growing in Africa, Asia, Latin America, Muslim world, and Oceania.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): By which year will Christianity no longer be the world's largest religion?
unanswerable