1999

4.3

1984

7.2

1995

8.0

1982

4.8

1982

5.7

1980

6.8

1990

8.5

1990

7.4

1996

5.4

1990

4.7

1989

5.0

1991

6.1

1981

7.0

1960

6.9

1988

5.8

1988

5.6

1985

7.2

1984

6.3