I'm not sure that I can speak to the motivations of different governments over time, but I can say that the tax credit is designed as additional or extraordinary support to the mining sector that supplements the ongoing permanent support available through flow-through shares to finance their exploration spending. The credit is an additional credit, on top of the deduction, that investors receive from a mining company. I think governments over time have wanted the opportunity to review current conditions in the sector to determine whether they merit extending this supplementary support.
