Year	Percent
1984	2.76423
1985	4.03756
1986	3.61374
1987	6.09244
1988	13.62862
1989	12.13068
1990	11.32876
1991	12.95373
1992	17.02576
1993	21.46162
1994	24.98694
1995	23.22039
1996	22.69875
1997	23.89222
1998	36.45587
1999	35.87584
2000	30.662
2001	27.87316
2002	28.75251
2003	23.50043
2004	24.91212
2005	28.96374
2006	38.15508
2007	33.61431
2008	33.15408
2009	30.08307
2010	35.38403
2011	40.34316
2012	37.87673
2013	38.1731
2014	40.75455
2015	33.95238
2016	33.2094
2017	34.3405