In retrospect I'd agree with Judith and Michael on the first answer but given that there are lots of different cultures and dialects I reckon it's more like 7000, given the population of the world being around 6 billion (and 9 million bicycles in Beijing?), it's just a simple mathematical calculation based on the Standard deviation of a probability distribution of demographic data and exponential estimation of the mean and median in the third quartile.
Actually it's another guess.
And they are....yea right!
Mike
Mike O
“The most affectionate creature in the world is a wet dog”