one unknown remains

After losing money in several ASX investments I've made a concerted effort to 'thoroughly understand' a business before i invest in it. Many hours of reading along with SWK's recent updates, now give me a picture of how this business operates. Clearly the drilling sector covers a number of areas, and some have far bigger barriers to entry than others. As has been noted on other threads, the key to SWK is their 'competitive advantage'. Other drillers cannot match SWK's advanced technology and effeciency. Over time i can't see why SWK won't continue to gain business from competitors. But for me, the one remaining (and it's important) unknown is: What is the total size of the UG Diamond Drilling Market here in Oz? Does SWK do 50%, 60% or perhaps more? I hope it's not too high, as the ability to expand revenue will depend on new mines entering production.... and we all know that takes years from the drawing board stage. However, some open pits are converting to UG i.e. IGR and SAR... and SWK will be targetting these new contracts hard.

Do any readers know what size the UG drill mkt is??