After 45 days without a triple-point loss, the Dow Jones took a major hit on Tuesday, with the index closing nearly 204 points down at 12,759. An approaching deadline on Greece’s bond swap, combined with some discouraging new economic data, appeared to give investors the jitters. The Dow finishes with its biggest decline of 2012 and since Nov. 23. Just two weeks ago, the market cracked 13,000 for the first time since 2008. It wasn’t a great day for the Standard & Poor’s 500-stock index or the NASDAQ composite index, either, which lost 1.5 and 1.4 percent respectively.