Year	Percent
1999	8.89
2000	7.2
2001	5.88
2002	5.54
2003	6.36
2004	6.32
2005	5.98
2006	5.76
2007	3.87
2008	3.35
2009	4.89
2010	5.7385
2011	5.5928
2012	4.2881
2013	4.1439
2014	3.0662
2015	2.9247
2016	2.8885
2017	3.3421