Year	Percent
1970	1.28382
1971	1.34231
1972	1.18698
1973	2.58721
1974	2.12291
1975	1.24121
1976	1.86482
1977	1.58635
1978	2.029
1979	2.85632
1980	1.98761
1981	2.24745
1982	1.39073
1983	1.67152
1984	1.72861
1985	2.16775
1986	2.82954
1987	3.88171
1988	4.57478
1989	3.38534
1990	2.55985
1991	2.06044
1992	2.21681
1993	2.86623
1994	3.83456
1995	4.23218
1996	2.96101
1997	4.81156
1998	9.64136
1999	14.54985
2000	17.72181
2001	4.77407
2002	6.83677
2003	4.02674
2004	5.36321
2005	6.34389
2006	5.28316
2007	12.04788
2008	12.34002
2009	-2.03111
2010	2.22874
2011	3.0856
2012	0.45166
2013	1.6881
2014	-3.7685
2015	-2.08545
2016	1.97742
2017	5.60845