An increase in existing home sales during May offers further evidence of an improved housing market, thanks in part to first-time buyers taking advantage of recent mortgage initiatives. The National Association of Realtors said the number of existing home sales rose to 5.35 million, up from 5.09 million in April, and up 9.2 percent from the 4.90 million transactions reported a year ago. That was the strongest sales rate since 2009. “We have seen...