2002

5.2

2011

6.1

2009

5.6

2011

5.0

2014

5.7

1998

7.5

2011

5.2

1991

5.3

2009

7.2

2013

5.9

2006

6.4

1993

6.6

2009

6.7

2013

6.2

1975

4.5

2016

6.3

1997

7.6

1968

7.1

2015

6.3

2012

4.3