Year	Percent
1991	1.96
1993	3.43
1994	3.38
1995	3.28
1996	3.2
1997	3.82
1998	5.16
1999	7.44
2000	7.84
2001	7.18
2002	6.31
2003	6.87
2004	7.31
2005	7.14
2006	6.36
2007	4.93
2008	3.98
2009	5.91
2010	6.44
2011	5.94
2012	6.12
2013	6.23
2014	5.6
2015	4.64
2016	3.54
2017	2.67
2018	2.03
2019	1.83
2020	2.41
