It's not necessary for the bottom quartile (which is what I was talking about) to change at all for the median to move, as long as the median stays above the hi

It's not necessary for the bottom quartile (which is what I was talking about) to change at all for the median to move, as long as the median stays above the highest value in the bottom quartile. The lower-middle quartile could absorb all of the change. A quartile is 25%, or a quarter, if you didn't know. My concern was for bottom quartile rents, since the bottom 20% of society is largely concentrated on the low end of that quartile, and they're largely the ones who actually suffer from high housing costs (as opposed to merely having fewer luxuries).