Year	Percent
1970	0.86596
1971	1.16576
1972	0.49922
1973	1.03446
1974	1.97196
1975	1.80488
1976	1.42781
1977	1.13473
1978	1.04666
1979	1.60121
1980	0.77415
1981	0.61117
1982	0.72226
1983	0.09356
1984	0.12785
1985	0.0236
1986	0.01744
1987	0.14027
1988	0.20575
1989	0.27826
1990	1.35026
1991	1.23275
1992	1.64165
1993	1.03455
1994	1.74184
1995	1.1388
1996	1.5263
1997	2.36623
1998	3.78855
1999	1.126
2000	1.31528
2001	1.2946
2002	1.42921
2003	-0.87582
2004	1.16978
2005	0.08358
2006	1.76402
2007	0.76115
2008	1.82584
2009	0.16895
2010	2.77349
2011	1.84861
2012	2.95643
2013	1.07909
2014	1.78002
2015	1.94211
2016	1.50038
2017	1.47745