Year	Percent
1993	2.4
1996	3.6
1997	1.1
1998	1.7
1999	3.4
2000	2.2
2001	1.3
2002	0.7
2003	0.8
2004	0.7
2005	0.5
2006	0.3
2007	0.1
2008	0.1
2009	0
2010	0.1
2011	0
2012	0
2013	0
2014	0
2015	0