over 99% of humans have an above average number of legs

False

ORLY? Take a ballpark guess of what the average number of legs per person is for the entire population of Earth? If you add up all of the legs that everyone has and divide it by the total number of people, what do you think that number might be?

Now what do you think the one percentile is for number of legs? What is the cut off for being in the lowest 1% of the population in regards to number of legs? If you arranged the world population in a line based on how many legs they had, from most to least, how many legs would the guy who is 99% of the way down the line have?

Is the one percentile higher or lower than the average?

Average number of legs per person... ballpark 1.99998 (some have more, some have less, but probably more with missing/partial legs than people with extra legs)

I would say that having both legs off at the hip would put you in the 1%.

Legless Joe has less legs than the average.

Now let's look at your statement:

over 99% of humans have an above average number of legs

You're saying everyone before Joe has more than 1.99998 legs, which is not true because there are people with 1 leg, people with 1.5 legs (off at the knee), etc.

Also, I gave you the benefit of the doubt by assuming there are more legless/partial legs than extra legs. Without that, your statement is just patently false.