1971

6.4

2008

6.6

2007

6.1

2004

7.6

2006

7.0

1968

6.5

1988

5.3

2007

5.2

2013

3.6

1986

6.1

2005

4.9

2000

7.3

1981

0.0

2001

6.1

2019

0.0

2003

5.7

2014

6.1

1992

5.4

2007

6.3

2004

6.2