1955

2.4

1981

7.4

2004

6.9

1970

5.0

2004

5.6

2006

5.7

2005

5.9

2021

6.2

1940

6.0

2007

6.1

1977

5.3

1966

6.3

2009

10.0

1997

6.8

1986

5.9

1966

7.1

1980

5.9

1955

7.3

1947

5.8

1956

5.4