Year	Percent
1999	10.11751
2000	6.57738
2001	8.45429
2002	10.1618
2003	14.35814
2004	17.69871
2005	23.43702
2006	27.48342
2007	23.34743
2008	10.52665
2009	22.69341
2010	35.12174
2011	29.77028
2012	24.80267
2013	25.31362
2014	29.82022
2015	25.82603
2016	22.83793
2017	21.74888