Actually more than median what you need is binning -- how many years for the 10th percentile income to pay off the 10th percentile house, and so on for each 10%

Actually more than median what you need is binning -- how many years for the 10th percentile income to pay off the 10th percentile house, and so on for each 10% band. For each year. That would be some really interesting data. I bet the effect is quite nonuniform.