1983

7.3

1964

7.1

2001

7.3

2010

3.9

2010

4.2

2007

4.0

1988

6.3

2000

6.3

2002

6.8

2000

5.2

1986

6.1

2017

6.9

2005

5.9

1976

6.6

2003

5.9

1975

5.5

1986

6.7

1999

6.5

1980

6.4

1997

6.1