1955

7.2

1990

6.7

1956

7.5

2002

6.0

1977

6.7

1974

7.0

1965

7.1

1962

7.8

1991

7.0

1966

6.8

2013

6.6

1971

7.1

1961

6.9

2013

6.3

2002

7.0

1941

7.1

1993

6.5

1984

6.5

1975

6.4

2012

6.9