As I mentioned, we don't actually produce a forecast of oil prices. We make an assumption that they stay near their recent levels. We do of course analyze the risks around that assumption. There are both upside and downside risks to the $60 assumption we made for Brent oil prices. On the upside, if you think about the cost of producing oil, a substantial proportion of world oil production today is too costly to be profitable at a $60 price. You can imagine that supply over time would disappear. That could put further upward pressure on prices.
On the downside, there could be further innovations in technology or cost-cutting measures that could put further downward pressure on prices. Overall, we see the risks to that $60 assumption that we made is tilted to the upside over the medium term.