Seven out of ten TV households are now measured via a TV ratings meter, according to estimates released Monday by Nielsen Media Research. Nielsen said its 56 metered markets - including one (Boston), which utilizes a people meter - now reach 69.58% of U.S. TV households, up from 68.96% in the 55 metered markets in Nielsen's sample last year. Interestingly, the new estimates show New York, the nation's largest TV market, expanded by 94,010 homes after a recent period of TV household attrition. Los Angeles, the nation's second largest market also expanded, picking up 84,200 households in Nielsen's 2003-04 season estimates. Nielsen Sept. 25 began collecting data from its new people meter panel in Los Angeles and is scheduled to release the first wave of that data to subscribers on Friday. The data, which currently is derived from a 540-household panel, is being released with a seven-day lag until March, 2004 when the L.A. panel will build to 800 households and will become the official ratings for the market. New York, the next market to convert to people meters, is scheduled to begin reporting preliminary people meter data in November and will convert to official people meter ratings in April 2004.