Year	Percent
1960	1.02516
1961	-1.45628
1962	-1.99015
1963	-1.6649
1964	-1.72604
1965	0.49436
1966	1.3728
1967	1.75816
1968	2.81242
1969	2.5921
1980	-2.0898
1981	0.77744
1982	0.77958
1983	-0.86428
1984	3.06872
1985	2.8333
1986	1.01805
1987	1.54027
1988	1.5573
1989	1.52239
1990	0.51749
1991	1.74616
1992	2.99037
1993	4.37946
1994	4.45404
1995	4.26834
1996	3.81154
1997	5.11028
1998	4.53732
1999	4.74961
2000	6.13021
2001	5.61498
2002	6.72094
2003	6.68699
2004	8.94953
2005	7.25113
2006	8.4645
2007	11.29642
2008	10.54293
2009	7.53074
2010	10.67916
2011	8.43483
2012	10.38486
2013	12.05333
2014	11.68731
2015	11.50841
2016	11.22241
2017	11.04926