I get the general idea -that we are much richer than we think if we look at things at the world level. But I don't believe their distribution.

I entered the UK median salary. And it said that I was the 58 millionth richest person in the world. That would be very, very odd. The UK has 62 million inhabitants. Even counting only half as having a salary (an obvious underestimate), that's already 16 million richer people in the UK alone. Probably around 80 million in the US. We still have quite a few countries to go and we are way already way over 58 million.

Then, of course, it does not seem to take the difference in purchasing power into account at all.

Earth provides enough to satisfy every man's need, but not every man's greed. Gandhi