1975

6.7

1992

6.3

1973

6.6

1974

6.2

1973

4.8

2003

5.1

1975

6.8

1974

6.5

1977

6.8

2009

7.3

1981

6.7

2007

6.9

1977

6.8

1972

6.7

1972

6.3

1976

6.2

2004

5.9

1972

6.7

2001

5.9

2003

5.7