Year	Percent
1992	27.77
1993	30.05
1994	32.56
1995	31.16
1996	28.5
1997	22.8
1998	21.33
1999	29.59
2000	35.67
2001	39.2
2002	41.61
2003	41.35
2004	40.07
2005	36.86
2006	29.77
2007	21.66
2008	17.29
2009	20.65
2010	23.67
2011	25.75
2012	26.49
2013	27.3
2014	23.87
2015	20.77
2016	17.66
2017	14.82
2018	11.75
2019	9.87
2020	10.83