2000

5.2

1990

6.2

2006

5.4

1991

5.5

1991

5.3

2007

6.6

2008

5.1

2002

5.4

2002

7.6

2007

7.5

1985

5.9

1965

6.6

2004

6.7

1994

6.5

1997

5.0