1961

7.6

1999

7.4

2003

5.9

1981

1.0

1988

5.0

1995

5.4

2004

5.6

1987

7.3

1990

7.5

1998

7.8

1971

6.4

1953

7.3

1980

1.0

1969

2.8

1996

6.6

2002

7.1

2005

6.3

1999

6.5

2001

6.7

1999

6.8