More than half of Americans say they don't get enough sleep.

57% of U.S. adults say they would feel better if they got more sleep, a new survey finds and women are more likely to not get enough sleep.

The Gallup poll finds 36% of women versus 48% of men saying they get the sleep they need and younger women have the biggest issue with getting enough sleep.

Younger women, at 27%, are much less likely than other age-by-gender groups to report getting adequate sleep.

The amount of sleep that Americans get a night has been shrinking for decades, according to the survey.

In 1942, 59% were getting eight-plus hours of sleep, while only 3% reported getting five hours or less.

By 1990, the percentage dropped to 27% with eight-plus hours of sleep and 14% reported getting five hours or less.

In the latest survey, 26% are still getting eight-plus hours, but the percentage getting five or less has risen to 20%. The number of people who say they get 6-7 hours a night is 53%.

The study asked what might be driving these downward trends in sleep and it cited a strong connection between stress and sleep quality.

Over the past 30 years, the number of Americans who are stressed has steadily risen.

The study did find that adults 65 and older are more likely than those who are younger to get the sleep they need.