1947

6.6

2008

4.5

2007

3.5

2003

5.4

2009

4.5

1968

6.5

2009

6.0

2007

5.4

2002

4.1

1968

4.8

1960

6.3

2008

7.3

1997

5.1

1993

6.4

2005

7.0

1982

6.4

2005

7.5

1963

7.5

1985

6.7

1984

7.2