Year	Percent
1961	2.50229
1962	0.05375
1963	0.68582
1964	3.84862
1965	1.47357
1966	6.56371
1967	11.72769
1968	3.31062
1969	5.45223
1970	0.05862
1971	4.22366
1972	6.36319
1973	25.43432
1974	25.44763
1975	15.46914
1976	7.7146
1977	37.25344
1978	12.30442
1979	13.02528
1980	13.053
1981	18.51303
1982	6.65951
1983	5.18819
1984	3.61902
1985	1.58683
1986	4.58259
1987	8.68414
1988	0.21692
1989	5.5014
1990	7.4706
1991	4.8271
1992	2.53568
1993	-1.19481
1994	2.37078
1995	1.31063
1996	3.56597
1997	1.35783
1998	3.21219
1999	1.81649
2000	-0.21327
2001	6.69815
2002	1.01705
2003	-3.1353
2004	4.01401
2005	2.94727
2006	3.01134
2007	8.40983
2008	0.01981
2009	-0.86789
2010	4.43625
2011	-0.33018
2012	1.08968
2013	2.20751
2014	-0.42839
2015	2.47363
2016	-0.09427
2017	1.52397