2005 was a good year for rating residential MBS, according to a new report from Moody’s Investors Service that shows the company’s one-year accuracy ratio jumped to 87.0 percent ending December 2005, up from 62.5 percent for 2004. Accuracy ratios are based on the loss experience of securities. “The one-year accuracy ratio in the all structured finance category trended up significantly in 2005,” Moody’s noted, with gains by residential MBS, asset-backed securities and global CDOs.…