Year	Percent
1961	-0.47289
1962	4.19534
1963	5.67491
1964	-0.59108
1965	3.70757
1966	0.20733
1967	-2.07658
1968	6.60486
1969	2.39571
1970	8.77885
1971	7.90249
1972	0.92448
1973	9.31303
1974	18.29678
1975	8.19242
1976	10.03771
1977	13.37827
1978	0.21978
1979	3.42146
1980	15.79275
1981	16.40574
1982	9.66326
1983	11.22977
1984	12.77206
1985	8.93084
1986	13.50928
1987	16.72387
1988	31.09181
1989	22.50948
1990	10.66083
1991	10.69237
1992	13.27642
1993	28.17467
1994	26.17188
1995	77.21958
1996	52.34561
1997	20.83484
1998	19.54848
1999	39.69078
2000	30.53395
2001	25.62247
2002	112.69365
2003	10.34609
2004	14.84663
2005	10.74124
2006	19.96726
2007	4.09972
2008	11.96467
2009	7.89982
2010	12.12718
2011	14.07576
2012	17.6561
2013	27.3004
2014	20.8837
2015	20.53466
2016	19.54413
2017	13.46151