Year	Percent
1980	16.20943
1981	19.09147
1982	13.38112
1983	14.27962
1984	12.70562
1985	10.92325
1986	10.63641
1987	10.18601
1988	5.89418
1989	8.32557
1990	13.00592
1991	10.90887
1992	8.36977
1993	7.74811
1994	8.66377
1995	5.57287
1996	11.036
1997	-2.42436
1998	5.31348
1999	0.29287
2000	1.09681
2001	10.86612
2002	11.67171
2003	11.22725
2004	10.32499
2005	11.29964
2006	10.37877
2007	9.45337
2008	9.11183
2009	9.99348
2010	31.08908
2011	42.03716
2012	27.47663
2013	13.76132
2014	13.68912
2015	15.52877
2016	20.12169