Year	Percent
1992	8.77
1993	10.36
1994	9.25
1995	8.9
1996	8.77
1997	7.82
1998	7.77
1999	6.23
2000	5.86
2001	5.19
2002	5.09
2003	5.27
2004	5.3
2005	6.39
2006	6.84
2007	6.85
2008	7.16
2009	9.14
2010	10.42
2011	10.16
2012	10
2013	9.1
2014	6.81
2015	6.03
2016	4.53
2017	3.69
2018	3.38
2019	2.97
2020	3.82