Ann: March Quarter Sales Results, page-85

SLR have had a short mine life for years, but continuously produce and replenish it. For underground (especially deeper) gold operations that is pretty normal as suitable drill access often requires development that only occurs 1-2 years prior to mining. Attempting to drill from surface is expensive and often leads to widely-spaced holes through mineralisation at poor intersection angles. So underground resources are only converted to reserves when nearby development is in place for drilling. This often requires specific drives for drill cuddies out of the way of production operations to allow good intersection of mineralisation with close-spaced short holes (and defers the drilling costs to later years). If it does not stack up then you don't have to put the expensive development in for mining. It is much easier and advisable to drill out an open pit mine 5-10 years in advance (best case would be immediately prior to each cut back), so that you are confident that mining the overburden to reach the ore for that cut-back is economically feasible. I am confident that in 10 years time the SLR assets will have produced more gold than REDs.