1962

7.3

1953

7.9

2001

7.8

2004

7.3

2007

6.3

1980

7.3

1981

7.4

1999

5.7

1997

6.6

1999

6.3

2002

6.0

1998

6.6

1973

7.0

1983

7.2

1994

7.0

1988

7.5

1993

6.7