Year	Percent
1984	34.04
1990	27.39
1991	29.13
1992	28.65
1993	27.34
1994	30.05
1995	29.2
1998	29.47
2000	36.36
2001	41.71
2003	44.2
2004	39.994
2005	34.7079
2006	34.6627
2007	30.8712
2008	28.4123
2009	26.6022
2010	26.3871
2011	22.3317
2012	23.6977
2013	23.9915
2014	23.9529
2015	26.241
2016	28.7227
2017	30.3611