Rising prices helped lift 1.7 million homes above water in 2012, including 200,000 in the final three months of the year, according to a report released today by real estate data and technology firm CoreLogic. An estimated 10.4 million homes remained underwater as of Dec. 31 -- about one in five (21.5 percent) of all homes with mortgages. But another 5 percent gain in home prices could lift 1.8 million additional homes into a state of positive equity, CoreLogic said.  In aggregate, total negative equity nationwide fell $42 billion last quarter to $628 billion, with just over half that amount consisting of first liens with home equity loans. The average amount of equity for all properties with a mortgage was 31 percent. But 2.3 million homes with "near-negative equity" (less tha...