1997

7.0

2000

6.3

2005

6.1

1967

6.6

1939

7.6

1998

6.2

1988

6.2

1960

7.5

1974

2.7

1949

5.0

1997

6.8

1989

5.3

1993

7.5

1963

5.9

1971

7.4

1974

7.2

1956

0.0

1979

6.1

1960

6.1

1962

7.8