Year	% of total reserves
1970	23.12402633296186
1991	422.910805197761
1992	555.0919070873242
1993	586.776964822218
1994	481.5589698389429
1995	357.7767459119161
1996	293.14342086208757
1997	263.6717821538297
1998	298.6521591705456
1999	252.0739969960379
2000	186.8923508626945
2001	153.95360899424446
2002	99.23381086566155
2003	93.89837461069492
2004	80.44831926416714
2008	29.795820847459336
2009	25.074806923737437
2010	22.107952431998463
2011	28.819707228106004
2012	26.28323878897318
2013	29.79922641670053
2014	27.689784417482056
2015	35.67736686049201
2016	40.59847100281097
2017	37.49263733982552
2018	16.190171284994907
2019	17.945282071158385
2020	18.266956596561762
2021	23.44942867048179
2022	20.61784647967967