Year	Percent
1985	3.45622
1986	3.69658
1987	3.62333
1988	4.18003
1989	3.25716
1990	4.43448
1991	4.5041
1992	4.8446
1993	4.59941
2001	8.92671
2002	7.56885
2003	7.21964
2004	9.32928
2005	8.79294
2006	10.34647
2007	9.05297
2008	9.20774
2009	7.2113
2010	7.37581
2011	5.93058
2012	5.61367
2013	5.78389
2014	12.26795
2015	20.24135
2016	16.24388