Year	Percent
1991	2.32
2002	7.25
2003	6.75
2004	6.49
2005	7.23
2006	6.03
2007	6.07
2008	5.48
2009	5.83
2010	6.54
2011	7.73
2012	10.41
2013	9.91
2014	11.56
2015	11.59
2016	9.57
2017	7.47
2018	4.36
2019	3.43
2020	4.69