2006

6.9

1990

6.4

1982

6.9

1987

7.3

1971

6.4

1984

7.1

2008

5.1

1960

7.5

1966

6.8

1962

7.3

1988

6.2

1962

6.9

2001

5.3

1984

7.5

2008

6.3

2011

6.5

1994

5.9

1989

6.7

2005

6.7

1979

7.8