Yes, it will be statistics. Basically, we're taking the province of British Columbia and we're saying, okay, if we draw the line in the sand at 300, these areas are higher-radon and those areas are lower-radon; and if we draw it at 400, these areas are higher-radon and those areas are lower-radon. The more area we have that is higher-radon, the more data we'll have from that area, and things will stabilize a little bit.
When you're talking about pretty unpopulated areas of the region, there are not that many lung cancer deaths in any given year, so it's definitely a statistical thing where the data get more stable as the threshold gets lower.