All US adults
18-24
25-34
35-44
45-54
55+
Several times a day
15
15
20
16
12
9
Once a day
13
10
13
18
13
9
4 to 6 times a week
16
12
17
20
12
14
2 to 3 times a week
21
26
20
19
22
22
Once a week
27
28
22
21
31
35
Don't know
9
9
8
6
10
12