1997

6.3

2003

5.3

2008

5.9

1979

6.1

1967

7.5

1993

6.2

1969

0.0

2007

6.7

2001

6.3

2003

6.1

1996

7.2

2004

5.3

2003

6.2

2007

4.1

1996

6.0

2003

7.8

2017

7.2

1970

4.2

1973

4.0

1952

6.4