Year	Percent
1975	3.21408
1976	1.55246
1977	1.88855
1978	2.46043
1979	1.61177
1980	1.89169
1981	1.61375
1982	2.24586
1983	3.0062
1984	3.71177
1985	5.35025
1986	4.2549
1987	3.87139
1988	4.24316
1989	3.33935
1990	4.34871
1991	3.44579
1992	3.90546
1993	3.6182
1994	4.01071
1995	3.14762
1996	5.24363
1997	2.82515
1998	2.59537
1999	2.16498
2000	2.03373
2001	1.71238
2002	1.95407
2003	1.23113
2004	1.03468
2005	0.93421
2006	0.96708
2007	0.72258
2008	1.17758
2009	1.04367
2010	1.3633
2011	1.00289
2012	0.72388
2013	2.06778
2014	0.64364
2015	3.14137
2016	1.89888