1999

5.1

1997

4.5

2003

5.8

1943

6.5

2007

6.0

2017

7.0

2009

6.1

2005

6.3

2009

6.6

2002

5.8

1992

6.1

2008

6.7

2005

7.2

1997

5.9

2002

6.2

1997

6.7

1964

7.0

1993

6.5

1957

6.4

1953

6.2