1940

6.3

2002

6.3

1951

7.1

1992

7.0

2000

6.8

1990

7.8

1975

7.2

1981

6.5

2004

7.9

1970

7.5

1983

7.1

2003

7.3

1977

7.2

1950

7.0

1993

7.4

1986

7.0

1982

6.7

1984

5.6

1986

6.4

1979

7.0