1990

7.7

2006

5.8

2008

6.6

1960

7.2

2000

6.5

1999

6.7

1965

7.2

2007

7.5

1976

7.3

2003

5.8

1950

6.8

2001

5.9

1979

4.8

2001

6.3

2004

7.0

2000

6.3

1969

6.0

1981

6.2

2021

4.5

2014

6.1