1964

7.4

1989

6.2

1980

7.2

2021

7.4

1991

6.7

1997

6.1

1995

5.9

2009

5.8

1969

7.1

2012

8.0

1975

6.8

1987

5.7

1979

7.3

1973

6.1

1970

7.0

1981

7.2

2009

5.7

2011

6.6

2011

5.5

2008

6.3