Year	Percent
1992	11.95
1993	12.67
1994	12.8
1995	11.69
1996	10.81
1997	10.13
1998	8.98
1999	10.65
2000	14.15
2001	15.86
2002	17.42
2003	16.86
2004	16.8
2005	15.73
2006	12.22
2007	8.35
2008	6.08
2009	6.92
2010	8.29
2011	8.24
2012	8.76
2013	9.04
2014	7.91
2015	6.64
2016	5.4
2017	4.22
2018	3.35
2019	2.89
2020	2.78