Year	Percent
1975	5.51896
1976	5.62713
1977	8.3811
1978	-2.17143
1979	12.67189
1980	86.11397
1981	9.0216
1982	-4.83844
1983	-11.42004
1984	-1.27417
1985	-2.46494
1986	-31.90475
1987	10.72996
1988	-7.66907
1989	8.69805
1990	8.40996
1991	-2.83728
1992	1.72688
1993	-2.95149
1994	-8.76363
1995	2.873
1996	4.48876
1997	8.58485
1998	-11.64857
1999	11.59398
2000	29.01571
2001	-5.5919
2002	0.37421
2003	6.10461
2004	15.88616
2005	18.76632
2006	10.04772
2007	1.12045
2008	12.69273
2009	-22.09142
2010	16.68828
2011	20.18051
2012	1.22165
2013	-2.82415
2014	-2.00588
2015	-17.46828
2016	-9.18101
2017	4.95524