City of the big disjunctions

Continuing in another connection with the exploration of real-estate listings that I discussed earlier ("Long is good, good is bad, nice is worse, and ! is questionable", 6/12/2013; "Significant (?) relationships everywhere", 6/14/2013), I stumbled on this curious factoid about the use of and and or in trulia.com's listings for the ten cities I've harvested so far:

So the descriptions in Chicago real-estate listings use "or" 2.4 times as often as New York City listings do; but NYC listings use "and" almost twice as often as Chicago listings.

For those who worry about statistical significance, here are some of the 95% confidence intervals for the rates (estimated by R's binom.confint(…,methods="exact")):

"and" lower"and" upper"or" lower"or" upperChicago207742154248305208Phila342863513126782922LA333443446227033035Atlanta260042732431443442NYC388473943820562197

As usual, I have no idea what this means, except that there can apparently be striking differences in surprising aspects of local linguistic subcultures.