June 18 (UPI) -- The Mortgage Bankers Association reported that May mortgage demand was down 4.5% year-over-year, despite lower interest rates. Refinance demand was also lower in May. " Economic uncertainty , rising mortgage rates and increasing competition from growing existing-home sales inventory likely dampened overall demand for new-home purchases in May," association vice president and chief deputy economist Joel Kan said in a statement. "Applications to purchase newly built homes fell to