Year % of total reserves 1985 0 1986 0 1987 0 1988 0 1989 2.2282041868381333 1990 3.6733698400873767 1991 1.4733385857105428 1992 1.0471620663357708 1993 1.745683903462603 1994 0.5791202746532411 1995 0.4410507731907351 1996 0.05471628662063637 1997 1.0597891773005872 1998 0 1999 0.6876834821894339 2000 0.4816888947677536 2001 0.009277522615918056 2002 0.28821004130685923 2003 1.2005028337858317 2004 0 2005 2.669004136496717 2006 2.9340314322316217 2007 2.5749250789730875 2008 1.0460208366520347 2009 0.5612343639665424 2010 0.5987192784558104 2011 1.0131150894295422 2012 7.856048819338948 2013 0 2014 0.2741174643878508 2015 0 2016 0.007717710412190357 2017 0.24928741460908432 2018 0.4368714054885715 2019 2.242945460768114 2020 0.10189816392159343 2021 0.3026856515484666