California, the largest mortgage market in the U.S., padded its lead by posting a 39.7 percent increase in GSE business last year, topping the 29.8 percent growth in overall Fannie Mae and Freddie Mac activity, according to a new Inside The GSEs analysis. The Golden State accounted for 22.6 percent of loans sold to the GSEs in 2015 and, not surprisingly, 62.7 percent of conforming-jumbo mortgages. In California, the average Fannie/Freddie loan was $310,185, trailing only Hawaii and the District of Columbia in size. Purchase mortgages accounted for just 29.0 percent of California GSE business last year, roughly a third less than...