Year	Percent
1960	-0.42535
1961	0.65175
1962	0.51237
1963	0.4238
1964	0.43019
1965	-0.6873
1966	-0.5188
1967	0.11382
1968	-0.01935
1969	-0.19685
1970	0.08875
1971	1.66384
1972	1.99284
1973	3.21712
1974	0.12017
1975	0.53292
1976	-0.83503
1977	-0.82605
1978	1.65409
1979	-0.14931
1980	-0.97789
1981	0.53326
1982	0.2217
1983	2.55668
1984	3.95906
1985	2.05212
1986	3.4032
1987	2.16692
1988	1.93692
1989	0.77793
1990	0.63518
1991	1.68177
1992	1.72239
1993	3.37433
1994	4.05421
1995	6.37866
1996	6.17797
1997	6.94918
1998	6.31073
1999	6.0663
2000	5.86849
2001	6.23172
2002	6.31653
2003	6.34048
2004	7.60001
2005	7.17254
2006	7.59051
2007	6.97635
2008	6.26706
2009	5.7613
2010	5.46754
2011	4.70426
2012	4.93126
2013	4.5077
2014	4.31564
2015	4.86166
2016	4.83883
2017	4.20712