Year	Percent
1999	16.87615
2000	15.6772
2004	12.41357
2005	13.69455
2006	14.09791
2008	15.44909
2009	16.06179
2010	18.18083
2012	14.9874
2013	15.9469
2014	16.22051
2015	14.91693