Year	Measure
1998	4.5
1999	4.5
2000	4.4
2001	4.1
2002	4
2003	3.7
2004	3.5
2005	3.5
2006	3.3
2007	3.5
2008	3.6
2009	3.7
2010	3.5
2011	3.38561