Year	Percent
1999	8.20272
2000	14.22237
2001	13.88587
2002	7.98885
2003	7.64343
2004	6.9487
2005	7.34015
2006	7.41856
2007	7.95693
2008	7.44154
2009	10.63567
2010	26.18705
2011	12.17017
2012	17.0952
2013	15.99785
2014	21.21319
2015	28.60623
2016	41.42456