Year	Percent
1989	3.62081
1990	4.44433
1991	4.08783
1992	4.12977
1993	3.15825
1994	3.434
1995	4.21175
1996	5.29926
1997	2.9446
1998	3.21285
1999	3.15208
2000	1.67315
2001	2.0284
2002	1.79431
2003	3.89328
2004	8.57821
2005	16.9718
2006	22.7306
2007	29.37188
2008	30.44966
2009	30.85647
2010	36.89683
2011	27.29083
2012	13.00137
2013	7.15269
2014	6.22516
2015	6.15092
2016	7.28219