10.0

1990

6.1

1989

7.0

1991

4.7

1981

6.5

1989

5.5

2000

5.1

2004

6.8

1952

6.7

1956

7.1

1990

6.1

1987

7.4

1989

7.3

1976

5.5

2010

6.0

1988

6.4

1994

5.9

1998

6.0

1973

9.2

1959

6.1