They kind of inherited it originally from the mining sector, because they receive 100% capital cost allowance for their developments. Originally most of the oil sands were developed essentially through open-pit mining, so they were treated the same as mining for tax purposes.
Now we're seeing more oil sands development take place through in situ, it's called. This means that they put hot steam into the ground and the oil comes up, and they just transferred the same tax treatment from the mining side to the in situ side in the mid-1990s.