1996

5.9

6.0

2009

6.8

2013

6.9

2019

7.7

1986

7.9

2013

7.2

2011

6.3

2012

7.8

1992

5.0

1999

7.6

2003

6.7

1977

6.5

1945

6.2

2010

6.0

1975

7.9

2015

7.0

2002

4.7

2017

6.9

2010

6.6