Year	Percent
1989	0.89005
1990	0.21732
1991	0.28602
1992	14.06786
1993	7.71075
1994	4.56305
1995	3.39517
1996	4.22353
1997	2.20277
1998	6.67022
1999	17.04677
2000	20.0271
2001	12.6761
2002	10.79099
2003	11.37169
2004	12.25393
2005	13.69288
2006	12.72755
2007	8.622
2008	9.23667
2009	7.44114
2010	8.07562
2011	8.05275
2012	6.65734
2013	5.39257
2014	6.4071
2015	8.03565
2016	5.17258
2017	5.3511