2007

8.1

2019

6.7

1999

7.0

2013

7.8

2008

7.4

2011

8.3

1991

7.7

2013

7.5

2012

8.1

2015

8.6

1998

8.5

2017

7.1

2020

7.0

2013

7.7

1990

6.8

2010

8.2

1994

7.0

1993

7.3

2001

7.0

1968

7.3