1981

0.0

2005

5.6

1980

6.5

2000

7.4

2005

8.2

1979

6.8

2005

5.9

1972

7.9

1986

7.2

1982

7.8

2006

6.8

1985

1.6

1990

4.0

2000

5.7

1972

7.1

1999

8.3

1978

6.8

1987

6.3

2002

7.3