1981

1.0

1996

4.7

1997

4.8

1987

4.3

1988

5.4

1995

3.8

1972

3.2

1991

4.7

1973

0.0

1980

1.0

1982

1.0

1977

2.5

2001

3.8

2002

3.4

1999

3.2

1970

3.8

1989

4.2

1998

2.4

1975

2.7

1978

5.0