1970

4.2

2000

5.7

1999

4.0

1974

6.0

1977

2.5

1993

5.5

2013

4.8

1979

6.0

1999

1.0

1980

1.0

1975

5.1

1982

4.9

1976

5.0

2007

0.0

1989

4.5

1985

3.8

1993

6.2

1999

5.2

2002

5.3

1988

5.4