1991

4.0

2017

5.9

2006

6.7

1970

3.8

1964

5.5

2014

4.8

1967

6.9

1995

6.5

2004

5.2

2003

6.6

1996

7.0

2001

7.4

1991

5.7

2013

6.2

2007

6.2

2006

6.2

1973

3.4

2014

6.0

2006

6.0

2005

5.0