1984

6.8

2003

6.8

1999

7.3

2001

7.0

2012

6.8

2012

8.6

2007

7.2

1987

7.0

2011

7.3

2002

7.6

2014

3.9

2020

6.5

1982

7.7

2004

8.0

2017

8.2

2008

7.5

1991

7.6

2015

4.0

1996

8.1

2009

8.1