By Dan Weil The 30-year fixed-rate mortgage averaged 5.30% in the week ended May 12. The woes continue to mount for the housing market, especially prospective homebuyers. The latest bad news: the 30-year fixed-rate mortgage averaged 5.30% in the week ended May 12, the highest since July 2009, according to housing agency Freddie Mac. That compares to 5.27% a week earlier and 2.94% a year earlier. This means a year ago, homebuyers were paying $294 in annual interest on every $10,000 of their mortgage loan, compared to $530 now. That’s an 80% increase. “The run up of mortgage rates since beginnin…