 About 3.0% of families and 4.3% of the population were living below the poverty line, including 4.6% of those under age 18 and 7.8% of those age 65 or over.In 2007, Plano had the highest median income of a city with a population exceeding 250,000 in the nation, at $84,492.As of 2010, Plano had a median income of $103,913 annually.