Year	% of total reserves
1970	0.49062228467744784
1971	0.6078355744736528
1972	0.7516704178438748
1973	0.014317857479246267
1974	0.0055311061555722045
1975	0.03373405514089294
1976	0.15988260859619674
1977	20.499667340661578
1978	24.029465882680178
1979	20.262727231614917
1980	21.54719730093109
1981	15.842726178057537
1982	24.472820566772974
1983	30.514768698785616
1984	62.26638816326485
1985	35.74955245772056
1986	25.072088010136124
1987	43.58052599218987
1988	89.09051801807642
1989	90.82443761815071
1990	263.4578402356617
1991	259.0695839099242
1992	117.9934122740941
1993	73.63485600985697
1994	72.15170113208171
1995	56.520931108722884
1996	59.51098477468651
1997	96.14925673458367
1998	104.6109534541785
1999	15.998921724051279
2000	23.672529802711406
2001	10.955842416177143
2002	5.892423243221115
2003	6.709817157527301
2004	4.864696741888117
2005	12.268724957182066
2006	7.262137964536347
2007	5.130707720342547
2008	6.660507663216271
2009	12.858892254647625
2010	13.478719052839711
2011	6.378943843226079
2012	1.568002750770104
2013	8.624286696070753
2014	8.27762897240968
2015	14.339346493183827
2016	30.60047721780435
2017	20.817497082385376
2018	18.793286703574665
2019	16.113634108592294
2020	13.399087979735688