Year	Percent
1990	12.20599
1991	11.02355
1992	10.43757
1993	12.57685
1994	12.50795
1995	22.37464
1996	38.5061
1997	36.2842
1998	26.54353
1999	34.83935
2000	41.40891
2001	35.89692
2002	37.00119
2003	36.439
2004	36.38251
2005	40.89682
2006	41.25854
2007	35.90343
2008	37.83695
2009	28.32515
2010	29.99508
2011	30.34043
2012	24.86371
2013	22.3593
2014	21.4838
2015	10.89957
2016	3.57574