1990

7.4

2011

6.9

1983

6.6

1966

7.2

1976

7.3

1982

7.6

1968

8.1

2012

7.9

1962

8.4

1969

7.2

1961

8.0

1987

6.5

2006

7.5

1968

7.4

1996

6.5

1967

7.5

1966

7.4

1980

6.6

1966

6.4

1988

7.1