Year	Percent
1989	0.10181
1990	0.19547
1991	0.84577
1992	1.06258
1993	0.84848
1994	1.07319
1995	2.0956
1996	1.26998
1997	2.17717
1998	3.54935
1999	2.84674
2000	2.9412
2001	4.1312
2002	3.23379
2003	5.66242
2004	6.74639
2005	7.15639
2006	8.29116
2007	6.43826
2008	6.53841
2009	10.95991
2010	6.60209
2011	7.30268
2012	6.94033
2013	7.50687
2014	6.13333
2015	5.68059
2016	7.24546