Year	Percent
1977	-0.39226
1978	0.79277
1979	0.1109
1980	0.09752
1981	-0.3117
1982	0.91978
1983	0.9673
1984	1.02575
1985	0.39934
1986	-1.78341
1987	1.22676
1988	0.50749
1989	-0.54242
1990	1.99202
1991	3.66489
1992	39.80924
1993	15.7233
1994	19.72545
1995	11.97181
1996	8.36398
1997	6.94131
1998	6.13214
1999	6.62104
2000	9.41533
2001	8.04272
2002	6.03493
2003	3.51786
2004	3.81719
2005	9.31044
2006	7.02116
2007	8.75694
2008	9.25831
2009	7.95605
2010	8.71009
2011	9.58066
2012	9.71183
2013	6.70762
2014	7.72647
2015	4.3493
2016	0.91321
2017	5.77183