Year	Measure
1998	2.7
1999	3.4
2000	3.4
2001	3.4
2002	3.7
2003	3.8
2004	4
2005	4.2
2006	4.7
2007	4.8
2008	5
2009	4.5
2010	4.3
2011	4.1943