1977

7.2

1980

6.6

2007

7.0

2004

0.0

1978

0.0

1997

5.8

1986

7.3

1981

5.0

1978

5.1

1975

8.0

1974

7.0

1982

7.0

1985

5.3

1969

0.0

1977

7.1

1988

5.3

1990

6.0

1991

5.5

1983

5.0

1974

6.4

2002

0.0

1992

6.5

1984

4.0

2005

8.7