Year	Percent
1998	0.84951
1999	0.86695
2000	0.9717
2001	2.7092
2002	5.39041
2003	5.68419
2004	14.38535
2005	15.90594
2006	20.42771
2007	17.41682
2008	7.09227
2009	7.57362
2010	8.52101
2011	7.60651