Year	Percent
1993	6.966
1994	7.86
1995	7.165
1996	6.42
1997	6.7696
1998	9.2826
1999	16.2648
2000	17.4489
2001	16.4274
2002	15.7043
2003	16.1791
2004	21.42
2005	19.3429
2006	16.6227
2007	10.5918
2008	9.833
2009	16.6088
2010	18.2436
2011	18.1477
2012	19.8618
2013	18.6452
2014	15.0425
2015	11.3153
2016	9.9088
2017	7.394