Around half of adults across the world hold antisemitic beliefs and deny the historic facts of the Holocaust. This is according to the latest edition of the largest global study of anti-Jewish attitudes by the Anti-Defamation League, a New York-based advocacy group.

The study surveyed more than 58,000 adults from 103 countries and territories representing 94% of the world’s adult population. It found that 46% of them—which when extrapolated to the global population would equal an estimated 2.2 billion people—display antisemitic attitudes. A fifth of the respondents haven’t heard of the Holocaust, during which six million Jews were killed, while 21% believe it has either been exaggerated by historians or it never happened.

According to the survey, the level of antisemitism in the global adult population has more than doubled since it was launched in 2014. The report is the latest among a number of surveys charting a steep rise in antisemitism across the globe.