Year	Percent
1998	14.33341
2001	18.27902
2002	17.97583
2003	19.52469
2004	10.14812
2005	21.11611
2006	20.0387
2007	19.30462
2008	22.49
2009	23.16314
2010	22.55143
2011	20.11754
2012	19.45532
2013	21.73635