1970

4.8

1972

5.0

1979

6.1

1980

5.5

1981

4.6

2007

4.3

1981

1.3

1981

5.6

1981

3.6

1999

3.5

1982

6.2

2008

4.2

1992

3.8

2002

3.3

2002

5.6

2005

2.0

1982

3.5

2003

4.8

2009

3.9

2000

5.6