Patching twice avoided
That number matters for one reason: at this income level, a homeowner calling about a noisy or jumping door is almost never looking to patch it twice. The houses themselves mostly date to around 1987, which puts them past the early galvanized-steel rollers that came standard on doors built before plastic-and-nylon combos took over, and well into the era where builders used sealed-bearing nylon rollers on steel stems.
