America’s Jewish population is becoming more Orthodox, a new Pew survey shows. The study found that 17% of Jews under the age of 30 are Orthodox, compared with only 3% of those over 65 and 7% of those between 50 and 64. The trend is largely attributable to higher birth rates among Orthodox Jews.

At the same time, the Pew survey found that the number of non-religious Jews—who identify themselves as Jews but profess no faith—has risen from 22% to 27% in the past eight years.