1977

5.3

2006

5.9

2000

7.0

2007

6.1

2005

5.3

2013

5.5

2006

5.5

1978

7.2

1985

5.2

2014

6.3

1971

5.2

2013

5.7

1974

5.9

2007

6.3

2012

4.9

2003

6.8

2007

6.4

1953

6.0

2005

5.7

1981

7.4