Year	Percent
1986	1.54
1987	1.9
1988	2.73
1989	3.93
1990	4.73
1991	5.45
1992	6.71
1993	5.74
1994	4.8
1995	3.4
1996	3.7
1997	4.11
1998	4.78
1999	5.04
2000	4.72
2001	3.61
2002	3.28
2003	3.61
2004	2.46
2005	1.93
2006	2.03
2007	1.44
2008	2.02
2009	3.19
2010	3.45
2011	3.3
2012	4.07
2013	3.66
2014	3
2015	3.36
2016	3.19
2017	2.84
2018	2.48
2019	2.72
2020	2.85