1997

6.5

2001

6.2

2005

5.9

2005

6.8

2008

6.2

1996

6.6

1973

6.7

1974

7.5

1971

5.5

1932

5.5

1965

6.7

1973

3.1

1973

5.3

1981

3.3

1977

7.4

1966

4.3

2007

5.6

1999

5.6

1955

6.0

1977

7.4