Year	Percent
1977	0
1978	1.96128
1979	0.00637
1980	5.19241
1981	15.73793
1982	20.90446
1983	24.62087
1984	21.77527
1985	29.80016
1986	9.84923
1987	39.24552
1988	21.35944
1989	62.79367
1990	34.81572
1997	29.04766
1998	33.49481
1999	26.91855
2000	25.84952
2001	28.1425
2002	24.55951
2003	27.19462
2004	40.06612
2005	37.15509
2006	31.67776
2007	31.91603
2008	12.00598
2009	9.8748
2010	6.29933
2011	5.33166
2012	33.45913
2013	10.95538
2014	13.39544
2015	2.78454
2016	2.89992