2000

5.2

1991

6.2

1966

6.8

2008

5.4

2003

6.9

2011

7.3

2002

5.0

1966

7.6

1952

7.9

1962

7.5

2008

7.6

2008

6.1

1934

7.5

2004

7.0

1989

5.1

2008

7.5

1973

7.7

1979

8.3

2006

6.3

1964

7.0