We have done calculations from time to time. If you say the spread of WCS to WTI is $40, which would be a pretty big spread—it's a lot smaller than that now—you multiply that by the exports of oil, you can get a pretty big number, well into the billions. If the spread is narrower, the number is a lot smaller. The key point is it's been very volatile.
On April 29th, 2014. See this statement in context.