Year	Measure
1998	5.7
1999	5.7
2000	5.7
2001	5.6
2002	5.6
2003	5.5
2004	6
2005	6.4
2006	6.7
2007	6.5
2008	6.6
2009	6.6
2010	6.5
2011	6.35361