http://en.wikipedia.org/wiki/New_Zealand#Demography

And, we're talking about less than 4.5m people.

Compare it with http://en.wikipedia.org/wiki/Demographics_of_Chicago , which has more people than live in all of New Zealand's 4 largest cities and has almost as many people as NZ's 16 main urban areas. And, that's not counting Chicago's suburbs.

Chicago is only moderately diverse for a large American city - there are less than 50 languages spoken by more than 1000 people.

See http://en.wikipedia.org/wiki/Demographics_of_Los_Angeles for diversity (which has more people than all of new zealand's major urban areas, and I'm still ignoring suburbs and other major adjoining cities.)