1987

6.1

1981

7.3

2001

6.7

1989

6.7

1966

2.1

1994

5.2

1970

4.8

1988

5.5

1959

6.5

1960

4.2

2007

5.6

1976

6.5

1982

8.1

1981

7.1

1962

6.9

1970

6.1

1985

7.1

1995

6.5

2009

6.3

2002

5.9