One out of three Americans do not get enough sleep, according to a new study from the Centers for Disease Control and Prevention, which found that sleep schedules varied by race, age and geography.

Over all, about 65 percent of Americans slept for at least seven hours each night, the threshold that the survey’s authors used to define a healthy sleep routine.

Among the demographic groups that reported lower-than-average rates of adequate sleep were non-Hispanic blacks, with 54.2 percent reporting an average of seven hours or more a night, native Hawaiians and Pacific Islanders (53.7 percent each), and American Indians and Native Alaskans (59.6 percent each).

The study, released on Thursday, was compiled from the responses of 444,306 people across the country, who were asked about their sleep routines as part of a 2014 survey.