Year	Percent
1984	6.34146
1985	9.76526
1986	7.70142
1987	14.02311
1988	31.89949
1989	31.99616
1990	24.51845
1991	25.2286
1992	27.105
1993	31.16719
1994	39.82233
1995	37.33408
1996	41.05842
1997	41.26475
1998	47.81367
1999	44.18261
2000	38.1753
2001	38.02628
2002	38.50239
2003	37.07166
2004	41.16763
2005	42.82891
2006	43.8063
2007	45.59832
2008	48.6951
2009	46.84776
2010	49.33631
2011	51.35554
2012	60.3084
2013	60.00604
2014	58.30519
2015	51.84625
2016	41.88242
2017	41.4861