Year	Percent
1970	20.08405
1971	6.61682
1972	9.99998
1973	8.61362
1974	4.95384
1975	-0.16438
1976	1.37778
1977	1.20689
1978	1.99733
1979	1.9272
1980	2.96638
1981	3.44984
1982	3.62614
1983	5.41921
1984	4.53227
1985	3.43938
1986	3.42913
1987	2.96385
1988	4.19843
1989	5.73504
1990	4.82691
1991	3.08177
1992	2.38237
1993	1.24535
1994	1.03494
1995	9.80507
1996	2.15882
1997	0.57884
1998	2.89293
1999	8.52716
2000	2.7403
2001	2.05072
2002	0.60939
2003	3.09558
2004	0.76094
2005	0.65391
2006	0.14179
2007	0.99066
2008	-0.26212
2009	3.60442
2010	0.20154
2011	-1.72274
2012	-0.29951
2013	0.08571
2014	-0.13178
2015	0.98589
2016	-0.1998
2017	-0.95064