Year	Percent
1992	18.81
1993	22.91
1994	20.91
1995	18.64
1996	19.39
1997	16.86
1998	15.19
1999	12.25
2000	12.26
2001	10.71
2002	11.42
2003	12.86
2004	14.4
2005	19.38
2006	19.15
2007	18.03
2008	19.51
2009	26.42
2010	26.42
2011	25.98
2012	28.2
2013	26.56
2014	20.39
2015	17.28
2016	12.93
2017	10.71
2018	10.17
2019	11.4
2020	12.76