Year	Percent
1961	1.44944
1962	0.60085
1963	0.94378
1964	-3.71634
1965	1.6911
1966	3.55521
1967	15.99159
1968	1.69284
1969	2.76225
1970	-1.42861
1971	-2.30943
1972	0.75549
1973	10.00483
1974	56.5209
1975	16.49667
1976	10.12872
1977	1.9218
1978	0.79736
1979	5.61665
1980	1.23518
1981	4.42518
1982	3.37447
1983	1.95734
1984	2.51789
1985	1.56725
1986	6.55451
1987	21.23842
1988	25.19562
1989	57.68448
1990	18.5396
1991	23.74884
1992	21.74547
1993	36.24943
1994	22.08015
1995	19.60084
1996	23.03749
1997	33.79422
1998	35.82524
1999	22.64049
2000	2.46177
2001	24.84446
2002	41.50893
2003	20.49654
2004	3.60113
2005	19.16353
2006	21.3005
2007	23.64391
2008	13.61866
2009	4.8786
2010	7.04321
2011	10.25458
2012	3.1301
2013	4.37807
2014	4.17354
2015	4.13663
2016	3.55552
2017	10.2499