1988

7.8

2007

7.6

2014

8.5

1991

8.3

2003

8.3

2007

7.9

1976

8.1

1998

7.8

2016

6.0

2011

8.3

2003

7.7

2016

7.4

1999

8.4

2010

8.2

1994

8.7

2019

7.8

2015

7.3

2016

7.4

2005

7.7

2010

8.4