1996

8.1

2009

6.5

2012

6.3

2011

7.4

2014

6.8

2002

7.9

2019

8.2

2015

5.3

1989

8.4

2013

7.5

1993

7.8

2017

8.6

2004

7.9

2015

8.6

1964

8.0

2005

7.9

2014

7.3

1987

7.7

2011

8.4

2012

6.6