1949

0.0

2006

5.6

1950

5.9

1956

5.1

1963

5.7

1988

4.9

1954

6.8

1989

5.7

1974

7.0

1965

5.7

1979

6.7

1961

6.4

1997

6.2

2001

7.7

2004

7.3

1997

4.8

1982

6.7

1953

7.0

1972

7.6

1957

6.2