BOSTON (AP) -- If you live in the Boston area, you may already know that some of your neighbors are wealthy. But over the next five years, the number of millionaires in the region is expected to increase by 50 percent, according to two wealth management companies. The Boston metropolitan area already has a high percentage of millionaires in its population -- 4.8 percent, or nearly one in 20 households -- a higher percentage than in New York, Chicago and Los Angeles, each with 3.7 percent of its population as millionaires. By 2009, the number of millionaire households in the...