1996

5.7

2008

7.1

2014

6.5

1987

5.5

2009

6.6

1990

6.1

1990

7.4

1983

6.1

2004

7.3

2004

6.9

2016

6.1

2013

6.7

1966

6.3

2011

7.2

1994

5.4

1984

6.6

2015

8.1

2010

7.9

1972

7.4