The average long-term U.S. mortgage rate fell for the fifth week in a row, more good news for prospective homebuyers grappling with an increasingly unaffordable housing market. The latest decline brought the average rate on a 30-year mortgage down to 7.22% from 7.29% last week, mortgage buyer Freddie Mac said Thursday. A year ago, the rate averaged 6.49%. The average rate on a 30-year mortgage is now at the lowest level it’s been in 10 weeks, when it was 7.19%. Still, it remains sharply higher than just two years ago, when it was around 3%.