1986

0.0

1955

7.2

2005

6.9

2007

6.1

2000

6.7

2003

5.5

2002

5.5

2002

7.2

1990

7.3

1991

6.9

2009

7.2

2002

6.4

1997

7.6

1968

7.4

1969

7.8

2003

5.8

1966

6.6

2007

5.3

2004

4.8

2006

6.8