1975

6.7

1992

6.3

1970

5.3

2003

5.1

1975

6.8

1981

3.2

2008

6.1

2007

4.5

2004

5.5

2008

5.0

1970

5.3

1977

6.8

1972

6.1

1972

6.3

2001

5.9

2017

3.5

1972

6.9

2002

6.4

2004

6.7

2006

6.2