1972

6.3

1996

5.7

1971

7.1

1996

6.7

2006

6.7

1972

6.5

2006

6.5

2002

6.3

2004

6.4

1989

6.1

1992

5.0

1991

6.6

2008

6.0

2004

7.2

2005

7.2

2014

3.5

1997

6.6

1996

6.5

2005

5.8

2006

4.3