1997

6.6

1982

6.6

1994

8.3

1983

8.2

2006

5.8

1956

7.7

1990

7.2

2000

6.0

1992

6.9

1990

7.5

1951

6.6

1951

6.3

1973

6.6

2003

8.1

1997

6.1

1999

5.6

1995

5.8

1991

6.8

1988

6.1

2002

6.3