2007

6.1

2006

6.3

2005

6.2

2003

6.5

2003

6.6

1990

6.7

1998

6.6

2017

6.8

2015

5.7

1976

4.8

1974

4.8

1940

4.4

2009

6.3

2008

6.4

2002

6.0

2002

4.8

1976

6.6

1978

7.0

2003

3.4

1998

6.1