Year	Percent
1981	0.14851
1982	0.13389
1983	0.12649
1984	0.17476
1985	0.37656
1986	0.35257
1987	0.3048
1988	0.25537
1989	0.35618
1990	1.7532
1991	9.44278
1992	29.8197
1993	66.02164
1994	88.57262
1995	39.3817
1996	46.8473
1997	62.08498
1998	50.14791
1999	52.69301
2000	56.26369
2001	57.42388
2002	53.3395
2003	41.49509
2004	35.33383
2005	20.61197
2006	14.88809
2007	12.93892
2008	9.41417
2009	19.47049
2010	9.47375
2011	5.57458
2012	6.4983
2013	6.42259
2014	7.36878
2015	8.29705
2016	12.87094
2017	24.33171
2018	6.42885
2019	6.14263
2020	23.55463
2021	4.99391