Year	Percent
1996	20.93
1997	14.9
1998	14.46
1999	13.79
2000	14.21
2001	13.82
2002	13.83
2003	12.06
2004	11.71
2005	10.03
2006	7.03
2007	6.05
2008	7.74
2009	17.51
2010	19.48
2011	16.21
2012	15.05
2013	11.87
2014	10.85
2015	9.87
2016	9.64
2017	8.72
2018	7.41
2019	6.31
2020	8.1