1992

6.2

1982

6.7

1975

6.3

2001

7.8

1983

5.9

1999

7.0

1981

7.1

1999

7.2

1991

6.2

1993

6.3

2000

4.5

2002

5.7

1998

6.5

1997

6.9

2002

5.3

2001

5.9

1995

6.7

1946

7.6

1968

7.1

1995

7.9