Year	Percent
1986	6.62254
1987	6.00143
1988	3.9453
1989	23.84936
1990	36.03861
1991	30.91504
1992	34.7456
1993	28.72278
1994	34.01313
1995	32.81286
1996	40.86849
1997	43.10271
1998	44.8483
1999	49.96625
2000	53.9215
2001	55.06193
2002	54.73913
2003	56.67326
2004	59.73104
2005	63.69949
2006	67.71681
2007	70.51787
2008	70.33669
2009	62.60888
2010	72.00236
2011	79.39087
2012	80.02862
2013	83.62614
2014	86.40476
2015	89.77925
2016	93.62394
2017	101.55526