Year	% of total reserves
1970	44.71840732907941
1971	40.08486297373424
1972	41.146198720634914
1973	28.930313135517967
1974	10.752224482929321
1975	7.341592637938654
1976	16.863504850635408
1977	56.50649318982155
1978	92.95025929946507
1979	89.2788370816217
1980	116.39240757937964
1981	133.49972019281026
1982	124.49338265547124
1983	120.81290472942014
1984	75.63852445061302
1985	63.94450714758154
1986	14.447259081286646
1987	35.49318412259798
1988	67.67202316184121
1989	26.312103982118547
1990	15.707689231346524
1991	15.517818977332599
1992	39.4163519785313
1993	34.196299916460354
1994	29.950671566289422
1995	28.589245309521743
1996	17.063838942349673
1997	47.894307004059264
1998	58.636461419699096
1999	49.5678222962786
2000	51.48794412011731
2001	63.80320169390337
2002	59.75654062743734
2003	33.90362340349377
2004	33.513151975607485
2005	33.916883764618724
2006	34.79233916919579
2007	58.21557066452145
2008	47.07814899008802
2009	60.709376181450146
2010	81.08812324693072
2011	87.37216730428426
2012	95.00241711813904
2013	147.18050055484375
2014	142.5642090775099
2015	263.0233606194592
2016	430.94512232837775
2017	451.25331924583725