1997

5.0

1970

5.6

1989

6.3

1959

0.0

1952

6.5

1967

7.1

2004

7.9

1998

6.9

2008

5.9

2006

4.8

2005

5.0

2005

6.9

2002

5.2

1999

6.5

1953

5.9

2005

6.1