Largely as a result, the average local property tax bill jumped more than $700 a year, or about 24 percent, to $3,962 from $3,206. By the end of Romney’s term, the combined state and local tax burden in Massachusetts grew to 10.6 percent of income from 10 percent, according to the Taxpayers Foundation, a Washington think tank. Pictured: Romney signed the state’s fiscal year 2004 budget.