1999

6.6

2011

8.1

2016

8.6

2004

7.9

2015

8.2

2011

8.3

2008

8.9

2001

8.0

1998

8.2

2010

8.6

1960

7.4

1996

7.5

2007

7.9

2005

8.2

2007

8.0

1994

8.4

2007

8.2

2013

8.7

2012

6.8

2019

8.5