Year	Measure
1997	8.61
1998	8.7
1999	8.8
2000	8.6
2001	8.7
2002	9
2003	8.7
2004	8.4
2005	8.5
2006	8.6
2007	8.4
2008	8.3
2009	8.2
2010	8.5
2011	8.50703