Conventional conforming mortgage originations – mostly financed by Fannie Mae and Freddie Mac – accounted for a record 66.8 percent of total single-family lending last year, according to a new market analysis and ranking by Inside Mortgage Finance. Mortgage lenders originated a whopping $1.273 trillion in conventional conforming mortgages in 2012, the highest level since the all-time record of $2.460 trillion was set back in 2003. Volume in the sector started strong and kept building throughout the year, including a 19.1 percent jump from the third to the fourth quarter. For the year, conventional conforming originations were...[Includes two data charts]