1965

6.0

2010

6.8

2011

7.4

2005

7.9

1994

6.8

2007

8.1

2020

7.8

2016

7.2

1980

8.6

2004

5.9

2010

6.8

2018

6.4

1993

8.0

2009

6.6

2015

6.2

1993

5.6

2016

7.0

2020

8.2

2018

7.6

1989

8.3