Year	Percent
1960	11.62573
1961	6.79964
1962	6.94
1963	10.03189
1964	6.32187
1965	16.7638
1966	7.4666
1967	5.94666
1968	3.98095
1969	4.39558
1970	3.38986
1971	3.40579
1972	1.94344
1973	2.81969
1974	1.75391
1975	2.39537
1976	2.91438
1977	3.01141
1978	1.95142
1979	1.54394
1980	1.49328
1981	1.30651
1982	1.45522
1983	2.40097
1984	5.40647
1985	3.92787
1986	2.40854
1987	2.41816
1988	4.07538
1989	4.36841
1990	7.33209
1991	6.54875
1992	8.23426
1993	2.9586
1994	1.21951
1995	1.27805
1996	1.45447
1997	1.32548
1998	0.67327
1999	0.51482
2000	0.60026
2001	1.04465
2002	0.96259
2003	0.92927
2004	0.72965
2005	0.62588
2006	0.72709
2007	-1.66324
2008	0.33283
2009	0.78081
2010	1.15209
2011	0.82779
2012	0.29072
2013	0.04589
2014	-0.87371
2015	0.04432
2016	0.09641
2017	0.16084