Year	Percent
1980	0.82127
1981	1.1716
1982	0.97031
1983	0.74401
1984	0.71426
1985	0.67238
1986	0.89755
1987	0.66645
1988	0.56231
1989	0.70291
1990	0.29302
1991	0.35611
1992	0.19436
1993	1.58907
1994	3.1271
1995	2.8048
1996	3.73606
1997	2.67486
1998	1.19582
1999	1.79708
2000	2.16021
2001	0.2876
2002	1.87833
2003	1.91944
2004	1.45344
2005	2.0421
2006	4.69454
2007	6.10472
2008	6.67206
2009	3.33278
2010	6.019
2011	6.07761
2012	5.37359
2013	4.14759
2014	4.75057
2015	3.55626
2016	3.40509
2017	1.83099