2006

3.5

1987

6.9

1975

6.3

2006

4.9

2004

4.9

1995

6.2

2000

6.2

2001

5.4

2000

6.8

2004

6.1

1981

7.1

1986

5.9

2006

6.0

2006

6.5

2015

7.0

1998

5.6

1950

2.0

1989

6.1

2000

5.2

2005

4.2