After a volatile year, when regulatory intervention caused some wide swings in the mortgage market, activity appeared to stabilise in December.According to the latest Australian Bureau of Statistics housing finance figures, the value of new mortgage lending rose 0.8 per cent in December, compared with the previous month (in seasonally adjusted terms).The value of new lending to owner-occupiers rose by 0.9 per cent in December, compared with the previous month, and the value of new lending to residential property investors rose by 0.8 per cent.Total new lending in December was worth A$33.5 billion - an increase of 6.4 per cent over the value of new lending in December 2014.The average loan size was $377,600 - down from $386,100 the previous month.First-home buyer participation in the mortgage market was 15.1 per cent.