Year	Measure
1998	3.1
1999	2.6
2000	2.7
2001	2.4
2002	2.7
2003	2.1
2004	2
2005	1.9
2006	2.1
2007	2.1
2008	2
2009	2.1
2010	2.2
2011	2.2337