Roughly 37% of all U.S. households own their homes completely, with no mortgage left to pay, according to data from Zillow, up 5.5% over the past decade. Since the Great Recession, younger Americans have been waiting longer to purchase homes, which has increased older generations’ share of the mortgage market. With many close to or already in retirement, a larger percentage of those homes are paid off. Zillow analysts suggest the numbers could change once younger buyers start jumping into the market.