Year	Percent
1970	0.7328
1971	0.79923
1972	0.65914
1973	0.54466
1974	0.50312
1975	0.19749
1976	0.21237
1977	0.18782
1978	0.22947
1979	0.2535
1980	0.29162
1981	0.46107
1982	0.29171
1983	0.29967
1984	0.1695
1985	0.24948
1986	0.18836
1987	0.32981
1988	0.32676
1989	0.44127
1990	0.39241
1991	0.20718
1992	0.73942
1993	0.59307
1994	1.03991
1995	0.78846
1996	1.86076
1997	1.23303
1998	2.1274
1999	1.38514
2000	4.33202
2001	2.99278
2002	0.14909
2003	2.71241
2004	1.29345
2005	25.72611
2006	3.12425
2007	17.72238
2008	1.46662
2009	3.57176
2010	-5.61521
2011	5.329
2012	1.27487
2013	0.10494
2014	0.38752
2015	-2.24497
2016	-7.66336
2017	3.30456