AS

HS

SE

ES

Tot

At least once a week

7

24

27

0

22

At least once every second week

22

22

29

10

25

At least once a month

45

35

28

61

34

At least once per semester

20

15

11

29

15

Less frequently than once a semester

3

3

2

0

3

I don’t know

1

0

1

0

1