Let me deal with the seasonal first. The demand for gasoline is typically higher in the summer months, so the product is worth more, and so the refiner is able to sell it for more. You tend to have an increase. The estimate is typically between 5¢ and 6¢ higher over the summer months compared to the rest of the year.
In terms of the really high peaks, if you see July 2005, that's explained by Hurricane Katrina, where you had over 20% of the refinery capacity in the U.S. that was put out for some time. So that explains that big peak.
The recent peak is explained largely, as I said, by a lot of unanticipated events that have shut out some of the refinery capacity. One of the largest ones actually was what happened in Ontario with the Imperial refinery in Nanticoke, which was out for five weeks. So that was an unplanned event. We've had other events in Canada and quite a few in the U.S. that have been the cause, for various reasons, that refiners had to shut down operations in times that were not planned.
What that has led to, as I mentioned before, is that because demand is so strong in the face of higher prices, inventories are getting drawn down; and the lower the inventory is, essentially the higher the demand is for that product in terms of people trying to secure product for the market.