Mayor Ed Murray addresses the crowd during a rally at City Hall after a Seattle City Council meeting in which the council voted on raising the minimum wage to $15 per hour in Seattle, WashingtonBy Eric M. Johnson SEATTLE (Reuters) – Seattle’s mayor unveiled an affordable housing plan on Tuesday aimed at creating 20,000 new living units for low-income city dwellers over the next decade, more than a quarter of them to be paid for by private developers. Mayor Ed Murray said his proposal was aimed at addressing an overheated real estate market, fueled in part by the growth of Seattle-based Internet retailer Amazon.com and other companies, that is pricing out low- and middle-income residents. Affordable housing has emerged as a top political issue ahead of fall elections in Seattle, a city of 650,000 residents.