1966

7.8

1990

6.1

1961

7.9

1971

7.0

1974

6.5

1985

6.9

2014

5.6

2009

7.1

1992

6.7

1973

8.0

1974

7.0

1987

6.9

1999

7.5

1935

7.5

1959

6.3

1984

6.2

1988

6.7

1998

6.6

2001

6.0

1987

5.5