Year	Percent
1991	7.24697
1992	13.16552
1993	13.58799
1994	6.94736
1995	6.84409
1996	12.15271
1997	6.25789
1998	5.60583
1999	3.31925
2000	10.70227
2001	3.73527
2002	12.23395
2003	1.70284
2004	7.16698
2005	5.30084
2006	4.26298
2007	5.88006
2008	11.44053
2009	7.23412
2010	6.81116
2011	14.62266
2012	5.00726
2013	2.33991
2014	2.49403
2015	3.08022
2016	3.62936
2017	1.63943