Year	Measure
1998	3.6
1999	3.9
2000	4.1
2001	3.6
2002	3.4
2003	3.7
2004	4.2
2005	4.2
2006	4
2007	4
2008	3.9
2009	3.4
2010	3.6
2011	3.42489