Year	Percent
1981	14.56871
1982	6.52926
1983	15.20739
1984	6.15989
1985	7.07123
1986	7.39284
1987	3.22303
1988	1.9373
1989	5.96106
1990	2.17518
1991	8.11944
1992	-6.76469
1993	2.833
1994	9.41679
1995	8.32074
1996	3.19909
1997	0.92383
1998	1.34639
1999	5.81165
2000	-4.46007
2001	8.6302
2002	4.17066
2003	5.11161
2004	3.38852
2005	0.31592
2006	3.11088
2007	3.54478
2008	5.27433
2009	3.62986
2010	3.87291
2011	2.62418
2012	2.27994
2013	1.32664
2014	2.65968
2015	3.42613
2016	6.94382
2017	0.77635