Year	Percent
1991	3.908
1992	10.934
1993	9.737
1994	10.081
1995	10.0112
1996	7.7799
1997	7.7626
1998	7.7075
1999	5.105
2000	3.7805
2001	4.4133
2002	2.9778
2003	12.1834
2004	7.3684
2005	6.0847
2006	7.6535
2007	6.2311
2008	7.4516
2009	11.9711
2010	14.1349
2011	10.6791
2012	12.3479
2013	7.7314
2014	6.5762
2015	6.7289
2016	6.3515
2017	7.0783