@Bloomberger this is quite funny............
" If the price of copper drops the Reserve can decrease. Reserve is based on the parameters you are going to mine for a set period and a set pit design based on current metal prices."
So in December 2015 the price of copper was around $US 2.10/lb but in December 2017 the Cu price is around $US3.20/lb. So despite a nearly 50% increase in the price of Cu, instead of increasing the reserve as per your statement above, they have decreased it by 58%.
How does this make sense??