1992

6.6

1998

5.7

2003

6.2

2005

5.8

2006

5.7

2000

4.5

1983

4.0

1998

6.5

2003

3.1

2007

5.6

2007

5.8

2003

6.1

1985

7.1

2017

4.9

2007

5.8

1997

6.0

2008

3.4

1979

5.8

2001

6.0

2019

6.7