1975

7.3

1989

7.5

2005

6.9

1986

6.4

2000

6.1

1989

6.2

2004

6.2

2005

7.2

1986

4.7

2006

5.3

2005

6.2

2001

6.5

1994

6.6

2000

7.1

1952

6.7

1979

6.6

1980

6.8

1980

0.0

2004

6.2

1994

6.2