Year	Percent
1991	0.51
1993	3.91
1994	3.55
1995	2.92
1996	3.62
1997	3.83
1998	3.78
1999	4.86
2000	5.26
2001	4.45
2002	3.89
2003	4.43
2004	5.43
2005	5.16
2006	5.32
2007	4.64
2008	3.88
2009	5.66
2010	6.5
2011	5.81
2012	5.83
2013	5.81
2014	4.93
2015	4.38
2016	3.82
2017	2.4
2018	1.96
2019	1.95
2020	1.99