Year	Percent
1961	13.93602
1962	178.86674
1963	145.84109
1964	114.73116
1965	228.81894
1966	-98.70383
1967	164.72184
1968	122.97281
1969	21.3532
1970	14.25307
1971	2.72474
1972	16.11984
1973	36.87848
1974	47.3105
1975	12.46806
1976	14.45679
1977	13.01236
1978	12.0649
1979	31.18719
1980	29.1455
1981	10.15071
1982	7.9505
1983	18.6127
1984	10.42183
1985	6.19136
1986	2.25377
1987	16.00382
1988	7.62911
1989	9.48503
1990	9.09395
1991	8.76704
1992	7.28886
1993	19.15258
1994	7.77657
1995	9.88205
1996	8.67651
1997	12.57138
1998	75.27117
1999	14.1612
2000	20.44746
2001	14.29572
2002	5.89605
2003	5.48743
2004	8.55073
2005	14.33179
2006	14.08742
2007	11.25858
2008	18.14975
2009	8.27475
2010	15.26429
2011	7.46594
2012	3.75388
2013	4.96599
2014	5.44317
2015	3.98024
2016	2.4804
2017	4.24446