2005

6.2

2012

6.1

2011

5.1

1999

6.8

2016

4.4

1987

7.1

1953

7.5

2012

5.0

2007

5.5

2013

5.7

2012

5.5

1981

6.3

2014

6.4

2015

6.6

1956

7.2

2011

5.6

2016

7.5

1994

7.1

1990

5.2