1990

7.7

2006

5.8

1978

5.9

1960

7.2

1950

6.8

2001

6.3

2000

6.5

2006

7.8

1981

7.5

2007

7.3

1966

6.7

2004

6.9

1965

6.3

1987

7.5

1973

7.5

2002

6.7

2016

6.3

1959

7.0

1971

6.2

2002

6.4