Year	Percent
1990	11.97236
1991	11.54516
1992	11.18848
1993	10.75779
1994	8.25353
1995	13.40854
1996	12.82808
1997	9.97631
1998	9.59423
1999	9.06988
2000	8.67488
2001	8.61983
2002	8.44739
2003	8.32653
2004	7.95035
2005	7.83134
2006	7.24485
2007	6.91135
2008	6.72923
2009	6.77391
2010	6.6475
2011	2.83822
2012	2.86674
2013	3.07738
2014	5.33042
2015	5.5701
2016	6.19265
2017	4.72174
2018	4.86512
2019	4.72749
2020	4.55644