1969

6.2

2007

6.4

2014

6.3

2008

4.3

1986

5.3

1996

6.7

1987

5.4

1986

6.1

2009

5.9

2008

5.2

1997

5.8

1984

5.8

2009

5.8

2004

6.4

2007

5.4

2007

4.5

1981

5.2

2004

4.9

1965

4.4

2001

6.9