It was slightly harder to get a home loan last month, according to the Mortgage Bankers Association. Their mortgage credit availability index slipped 0.1% in December from the previous month, led by a 7.2% decrease in conforming loan credit. The two bright spots were a 2.1% increase in government mortgage credit and a 1.4% rise in jumbo loan availability. Each of those ategories have been growing for several months, a helpful trend for first-time homebuyers.