Year	Measure
1998	9.3
1999	9.2
2000	9.1
2001	9.2
2002	9.4
2003	9.6
2004	9.5
2005	9.7
2006	9.6
2007	9.2
2008	8.9
2009	8.7
2010	8.5
2011	8.27403