1993

4.9

1985

6.2

2008

8.5

2009

6.6

1977

6.8

1974

6.5

1966

6.6

2001

6.9

1964

7.5

1959

8.1

1990

6.3

1957

8.3

2000

7.2

1984

7.9

1927

8.1

1999

7.0

1967

6.6

1955

7.8

1997

7.6

1950

6.6