Mortgage insurance activity increased dramatically during the second quarter of 2012, with private MIs gaining ground on the government-insurance programs, according to a new ranking and analysis by Inside Mortgage Finance. A total of $133.22 billion of home mortgages were originated with some form of primary MI coverage during the second quarter, up 22.9 percent from the first three months of the year. It was the biggest quarterly output of primary MI since the middle of 2009, and it lifted insured mortgage originations to $241.64 billion in the first half of the year, up 36.1 percent. Despite a relentless assault on their financial health that has driven three companies into runoff mode, private MIs racked up...[Includes three data charts]