Year	Percent
1998	4.2
1999	4.48
2002	5.74
2006	4.74
2007	4.44
2008	3.92
2009	5.09
2010	5.22
2011	8.32
2012	8.36
2013	9.14
2014	9.79
2015	8.71
2016	8.14
2017	7.85
2018	7.58
2019	6.09