1971

3.0

2004

6.5

1996

8.0

2007

6.1

2006

7.8

2008

6.0

1995

7.6

1987

6.2

1975

5.8

2001

4.5

2009

5.2

2009

4.7

2004

7.8

2008

4.9

2009

4.6

1999

5.0

2019

8.0

2016

7.0

1954

6.3

2001

4.3