1987

8.3

2016

6.6

1951

7.2

2007

6.5

1997

4.6

2005

5.0

1983

7.1

1995

6.3

1998

7.0

2013

7.6

2010

7.8

2003

7.3

2007

7.0

1970

7.3

1981

7.1

2001

7.9

2001

6.4

2011

8.0

2015

6.1

2013

4.8