1997

7.0

2006

7.0

1955

7.3

1956

7.1

1957

7.2

2007

6.3

1981

7.0

1968

7.5

2003

5.4

1973

9.0

2008

5.2

1993

6.1

1981

0.0

1979

1.7

1977

5.6

1989

8.0

1992

4.7

1957

4.0

2008

6.3

1990

6.7