Year	Percent
1998	23.11
1999	20.38
2002	27.1
2006	29.87
2007	24.8
2008	25.04
2009	24.78
2010	24.31
2011	29.3
2012	34.43
2013	34.11
2014	32.24
2015	31.56
2016	30.81
2017	29.55
2018	24.71
2019	19.23