Paragon reported that rental yields were remaining steady at 6%, with rents up 2.4% over past year and total annual returns averaging 10.3%, up from 9.4% three months ago. "Buy-to-let landlords are adding property to their portfolios at attractive prices as the housing market softens," said Paragon in its September buy-to-let index. According to Paragon research, landlords plan to increase …