the United States where the number of those who leave these religions is greater than the number of those who convert to it, and most people who leave Islam become unaffiliated, according to same study ex-Muslims were more likely to be Christians compare to ex-Hindus or ex-Jews. According to the religious forecast for 2050 by Pew Research Center, between 2010 and 2050 modest net gains through religious conversion are expected for Muslims (3 million) and most of the net gains through religious conversion for Muslims found in the Sub Saharan Africa (2.9 million). Darren E. Sherkat questioned in Foreign Affairs whether some of the Muslim growth projections are accurate as they do not take into account the increasing number of non-religious Muslims. Quantitative research is lacking, but he believes the European trend mirrors the American: data from the General Social Survey in the United States show that 32 percent of those raised Muslim no longer embrace Islam in adulthood, and 18 percent hold no religious identification. Many Muslims who leave Islam face social rejection or imprisonment and sometimes murder or other penalties. According to Harvard University professor Robert D. Putnam, there is increasing numbers of Americans who are leaving their faith and becoming unaffiliated and the average Iranian American is slightly less religious than the average American. According to Public Affairs Alliance of Iranian Americans, the number of Iranian Americans Muslims decreased from 42% in 2008 to 31% in 2012 according to a telephone survey around the Los Angeles region. A June 2020 online survey found a much smaller percentage of Iranians stating they believe in Islam, with half of those surveyed indicating they had lost their religious faith. The poll, conducted by the Netherlands-based GAMAAN (Group for Analyzing and Measuring Attitudes in Iran), using online polling to provide greater anonymity for respondents, surveyed 50,000 Iranians and found 32% identified as Shia, 5% as Sunni and 3% as Sufi Muslim. A survey conducted by Pew Research Center in 2017 found that conversion has a negative impact on the growth of the Muslim population in Europe, with roughly 160,000 more people leaving Islam than converting into Islam between 2010 and 2016. According to a religious forecast for 2050 by Pew Research Center conversion does not add significantly to the growth of the Muslim population in Europe, according to the same study the net loss is (−60,000) due to religious switching. See