Year	Percent
1970	0.33331
1971	-0.08464
1972	-0.7978
1973	0.30543
1974	0.08095
1975	0.089
1976	0.08377
1977	0.02724
1978	0.0814
1979	0.0935
1980	0.32139
1982	0.09277
1985	-0.11365
1988	0.07221
1989	-0.03336
1990	-0.1373
1991	0.0301
1992	0.10499
1993	1.69542
1994	2.21029
1995	2.1057
1996	2.00179
1997	2.79137
1998	3.18916
1999	2.33723
2000	2.59476
2001	2.59389
2002	2.98853
2003	3.19082
2004	3.72044
2005	4.21362
2006	6.47982
2007	6.44528
2008	5.11876
2009	4.63193
2010	2.69424
2011	4.43246
2012	5.21491
2013	4.45537
2014	3.87868
2015	2.7217
2016	2.59856
2017	2.7017