1934

4.1

1962

6.0

1990

7.7

1966

7.1

1999

7.1

2006

5.8

2009

6.6

2002

5.4

2001

7.3

1998

6.9

2002

6.2

1960

7.2

1975

6.9

2002

6.1

2000

7.2

1999

6.6

1998

7.2

2006

6.7

1986

6.9

2005

7.7