Year	Percent
1961	0.45807
1962	1.41421
1963	2.06116
1964	2.59925
1965	3.35959
1966	4.98063
1967	4.40158
1968	3.63583
1969	4.50579
1970	6.05664
1971	4.83185
1972	5.90013
1973	9.68672
1974	15.1981
1975	10.69515
1976	9.49691
1977	6.79654
1978	6.60297
1979	9.98552
1980	10.0716
1981	10.77663
1982	8.83802
1983	5.76262
1984	3.52795
1985	3.32836
1986	3.06726
1987	4.76103
1988	4.54445
1989	4.71334
1990	3.42334
1991	3.09421
1992	1.50147
1993	1.30294
1994	1.47034
1995	2.26058
1996	1.74455
1997	1.14132
1998	-0.18044
1999	1.90389
2000	4.34127
2001	1.65824
2002	1.24423
2003	3.25594
2004	3.28022
2005	3.14704
2006	2.61343
2007	3.31878
2008	4.00498
2009	-2.29425
2010	2.87406
2011	3.24205
2012	1.22125
2013	1.58516
2014	1.97054
2015	-0.7556
2016	0.61217
2017	2.2731