Year	Percent
1970	0.09967
1971	-0.02957
1972	-0.05207
1973	0.03506
1974	-0.00196
1975	0.63986
1976	0.0859
1977	1.60402
1978	2.62308
1979	3.0009
1980	2.84856
1981	0.43989
1982	-0.14926
1983	0.10975
1984	0.0701
1985	-0.16695
1986	0.62924
1987	0.68001
1988	0.56979
1989	0.44674
1990	0.44672
1991	0.2886
1992	0.08775
1993	0.67657
1994	0.88414
1995	0.8115
1996	0.66681
1997	0.52733
1998	0.64642
1999	0.98107
2000	1.15157
2001	1.48527
2002	1.32181
2003	3.34327
2004	2.57712
2005	4.76089
2006	7.70374
2007	5.80394
2008	7.05379
2009	5.06174
2010	5.43899
2011	5.60875
2012	11.78967
2013	1.31257
2014	6.69239
2015	4.56622
2016	-0.72893
2017	-1.56404