Year	Percent
1990	0.78473
1991	1.16319
1992	1.7242
1993	2.27167
1994	4.86278
1995	9.23709
1996	16.41935
1997	21.6164
1998	30.0932
1999	35.84872
2000	43.07916
2001	49.08083
2002	58.7854
2003	61.69712
2004	64.75826
2005	67.96805
2006	68.93119
2007	75
2008	74
2009	71
2010	71.69
2011	69.72946
2012	74.7
2013	71.4
2014	73
2015	74.5542
2016	76.17674