1981

6.4

1984

5.8

1973

6.4

2005

5.5

1987

4.0

1990

5.7

1948

7.0

1942

5.8

1969

6.4

1943

6.2

1939

6.7

1957

6.8

1967

6.5

1974

7.6

1974

6.2

1984

5.9

1996

5.2

1971

5.4

1964

6.1

1971

4.6