Year	% of total reserves
1991	57.5542453043077
1994	59.908396214619714
1995	55.63974815598174
1996	52.160071459688275
1997	44.715097564564694
1998	38.944633125214054
1999	34.59408622103619
2000	29.073777340575734
2001	35.94613166694574
2002	28.30158990757312
2003	26.562475668896184
2004	21.915183298216885
2005	20.51251679474803
2006	18.102395659460857
2007	17.547508343034455
2008	13.510948732782007
2009	12.2197790788196
2010	18.49406072181659
2011	22.29655827013159
2012	22.129469741814738
2013	25.95723995337667
2014	29.72068785481283
2015	23.423673716206554
2016	24.61142127535764
2017	28.886857050857326
2018	33.380280831851636
2019	32.52242196637496
2020	31.58963511989527
2021	35.952750112765926
2022	34.11355472501441