Belief in God is declining in the US, a new Gallup poll shows—although the vast majority of Americans still identify themselves as believers.

A May survey found that 81% of respondents said that they believe in God: the lowest number since Gallup began asking the question in 1944. The figure was 98% in the 1950s and 1960s, and remained over 90% as recently as 2011.

The percentage of Americans who said they did not believe in God was highest among young adults, college graduates, and self-identified liberals.