2007

4.9

1997

6.1

2004

6.0

2010

6.9

2019

8.7

2013

5.9

1984

6.5

1975

6.7

2007

5.7

1989

5.1

2013

6.1

1979

7.3

2011

4.5

1987

8.0

2002

6.0

2009

4.5

2008

6.4

2003

5.3

1991

6.2

2017

5.9