1996

2.0

1991

3.5

1997

5.4

2013

0.0

2015

5.0

1994

7.0

2006

6.2

1971

6.4

1970

6.1

2004

6.1

2014

7.1

2003

6.3

1993

6.1

2012

6.0

1992

3.4