Year	Percent
1991	1.49
1994	1.89
1995	1.85
1996	3.12
1997	3.3
1998	2.36
1999	3.74
2000	6.1
2001	4.83
2002	2.45
2003	3.85
2004	2.94
2005	4.22
2006	2.53
2007	3.27
2008	4.03
2009	3.57
2010	3.96
2011	6.26
2012	6.16
2013	7
2014	7.79
2015	7.76
2016	6.47
2017	6.39
2018	4.89
2019	4.51
2020	3.75