2000

7.1

1985

5.4

1970

6.9

2005

5.9

1969

4.1

2003

5.8

2004

6.6

2003

6.4

1991

7.3

1974

5.7

1980

5.7

1963

7.0

1983

5.6

1986

4.8

1985

6.2

2004

5.6

1996

6.7

1990

6.7

2007

6.4

1950

6.6