1979

5.7

2001

6.0

1982

4.0

2010

4.6

1991

5.7

2004

6.3

1992

6.6

1997

6.0

2021

5.5

2003

3.1

2007

5.6

1998

5.7

2000

4.5

2006

5.7

2008

3.4

2009

4.6

2005

5.8

2007

5.8

1983

3.9

2007

5.8