Year	Percent
1991	1.3015
1992	3.70055
1993	3.19928
1994	6.80406
1995	4.91184
1996	7.28803
1997	3.61434
1998	5.18101
1999	5.06435
2000	9.49336
2001	7.8095
2002	7.80354
2003	8.40913
2004	7.31947
2005	8.50023
2006	11.23332
2007	14.82353
2008	16.87833
2009	12.46449
2010	16.99394
2011	15.43737
2012	7.62143
2013	7.91528
2014	5.18362
2016	5.91538