Year	Percent
1990	4.03289
1991	3.03145
1992	1.57791
1993	2.35385
1994	3.39917
1995	3.58529
1996	4.0386
1997	4.43018
1998	4.49828
1999	3.27886
2000	3.88132
2001	4.94036
2002	10.64697
2003	3.59829
2004	3.20422
2005	2.8994
2006	3.24175
2007	5.50939
2008	4.15034
2009	5.31064
2010	5.69922
2013	3.7586