Year	Percent
1990	10.16
1994	11.79
1998	10.76
2003	9.99
2004	8.81
2008	8.37
2012	11.53
2013	12.44
2014	11.45
2015	11.2
2016	10.82
2017	9.51
2018	7.2
2019	6.02