9/3/96-11/4/96

9/7/04-11/1/04

9/8/12-11/5/12

%

%

%

Every week―more than once a week

13.0

14.4

9.9

Every week―once a week

12.5

11.7

12.6

Almost every week

11.5

11.2

11.6

Once or twice a month

14.4

15.1

10.4

A few times a year

17.8

15.5

14.9

Never

30.3

31.0

40.0

Don’t know

0.2

0.0

0.1

N

4518

4723

15,969