Commercial banks and savings institutions reported an unexpectedly strong $4.515 billion in mortgage-banking income during the fourth quarter of 2015, according to a new Inside Mortgage Trends ranking and analysis of call report data. The industry’s fourth-quarter results represented a solid 18.8 percent increase over the previous quarter, and it brought full-year mortgage-banking income to $18.474 billion – an 11.8 percent gain over 2014 ... [Includes one data chart]