How on earth can you possibly know what the fuel bill for Ryanair will be,
I don't know... maybe because they state the
exact figure (791.3 million euros ($1.23 billion).) in their annual results and a simple maths shows what the un-hedged cost will be, given basically the same schedule.
Here's the figures
Ryanair profits fall on fuel costs, takeover bid: Associated Press Business News - MSN Money
You also point out that people do not have to fly, in particular, those who use short-haul. Which book of facts did that come from, or was that also plucked from the crystal ball?
Every heard of cars, ships or trains?