Africa and Australia are included where?

Do scooters/motorcycles count as cars? Because I would think some countries would be a lot higher if that was the case

The world average is always bad because of the same guys.

What's wrong with Mexico?

One interesting aspect is that while high fuel prices are very bad for poor countries, it could be that the hit is somewhat dampened by the fact that e.g. most people im Asia use fuel for transport in a much more efficient way than the US. If you share a bus ride with 100 other people and only need to travel 10 kilometers, this might eat less percents of your relative income than when you need to daily travel 100 miles alone in a supertruck.

Which is also a big advantage of Europe compared to the US.