1985

7.1

1992

6.9

2003

7.3

2011

6.7

1979

6.2

2004

6.8

2002

5.6

1982

6.8

1988

5.8

1969

7.1

1983

4.5

2012

7.6

2017

6.5

2009

5.6

2014

7.4

2001

6.7

1982

5.8

2012

6.4

1980

6.6

1930

7.3