Year	Measure
1998	3.9
1999	3.7
2000	3.5
2001	3.7
2002	3.7
2003	3.7
2004	4
2005	4.3
2006	4.7
2007	4.9
2008	5
2009	4.5
2010	4.3
2011	3.97162