Year	Percent
1976	1.11067
1977	2.85841
1978	6.57969
1979	2.76023
1980	2.87168
1981	3.68043
1982	6.84863
1983	6.98226
1984	6.49296
1985	7.04856
1986	8.4341
1987	9.00128
1988	11.0535
1989	16.09679
1990	15.00323
1991	11.65658
1992	9.30764
1993	8.701
1994	8.04353
1995	7.91361
1996	6.64473
1997	7.0406
1998	8.08741
1999	8.171
2000	7.59374
2001	7.87272
2002	10.30127
2003	10.28878
2004	9.1529
2005	8.46083
2006	10.19991
2007	8.8831
2008	8.4574
2009	10.09015
2010	10.56075
2011	9.17714
2012	10.25763
2013	8.80302
2014	8.15327
2015	8.27466
2016	8.92599