Year	% of total reserves
1980	15.914545051693205
1981	13.82633715853302
1982	6.311081885356154
1983	5.999064779397874
1984	8.234508043900181
1985	9.251507182853228
1986	6.637926083344177
1987	5.923182008094111
1988	10.660739771071052
1989	4.0818198301334485
1990	3.8590787529537893
1991	2.8506809829012787
1992	3.02231818854212
1993	1.9714630670964208
1994	1.28270142411897
1995	0.8757729936688379
1996	0.8686105750882687
1997	0.6996211594636194
1998	0.7065721016744989
1999	0.8007098818400399
2000	23.211789129037392
2001	22.251603735664307
2002	14.026618559203389
2003	0.21723371299844532
2004	1.5952007413717975
2005	1.3484594231458311
2006	0.3037659898728093
2007	0.19944945202614475
2008	0.20586080534893475
2009	0.19980500134472062
2010	0
2011	0.44252882813660765
2012	0
2013	0.0007196189387572904
2014	0.020073227481815625
2015	3.315508863962436
2016	4.147761604663394
2017	0.058996304751789984
2018	0.0698803676173904
2019	0.04687271080657043