Year	Percent
1978	5.6875
1979	1.40431
1980	0.82209
1981	3.40537
1982	5.28442
1983	9.59897
1984	22.59128
1985	11.24289
1986	12.09527
1987	6.50869
1988	7.47071
1989	6.3064
1990	4.80305
1991	3.99799
1992	3.20344
1993	3.86508
1994	3.41912
1995	3.3606
1996	3.12301
1997	6.99315
1998	3.6592
1999	3.99221
2000	4.22309
2001	4.61677
2002	4.31505
2003	3.68988
2004	4.1823
2005	6.3228
2006	5.70039
2007	4.04164
2008	4.677
2009	5.71996
2010	4.01398
2011	3.56083
2012	3.31475
2013	2.57833
2014	2.62151
2015	3.7641
2016	3.65646