1934

4.1

1990

7.7

1966

7.1

1999

7.1

2006

5.8

2008

6.6

2009

6.6

2002

5.4

2001

7.3

2002

6.2

1997

6.8

1960

7.2

1987

6.4

1975

6.9

1999

6.9

2002

6.1

2000

7.2

1999

6.6

1998

6.4

2006

5.4