1969

4.9

1972

6.8

1994

7.2

1979

6.9

1985

6.7

1980

6.8

1959

7.5

1986

6.1

2004

7.1

1976

6.0

1985

7.5

1999

5.8

1959

5.0

2005

7.8

1980

5.0

1979

6.5

2001

6.7

1997

8.4

2006

8.2

2000

7.7