The mortgage market finished 2015 with growth in lending to residential property investors well within the target range of ten per cent set by regulators, but with a number of individual lenders still struggling to meet that target.According to the latest Reserve Bank lending figures, lenders' investor mortgage balances grew by 0.3 per cent in December, compared with the previous month.Over the 12 months to December lenders' investor mortgage balances grew by 8.5 per cent. The annual growth rate peaked at 11 per cent in May and June.Owner-occupier balances grew by 0.7 per cent in December, compared with the previous month, and by 6.8 per cent over the 12 months to December.Overall lender's mortgage balances grew by 0.5 per cent in December, compared with the previous month, and by 7.5 per cent over the 12 months to December. The annual growth rate has been steady at 7.5 per cent since August.Despite the overall decline in the rate of growth in lending to property investors, Australian Prudential Regulation Authority figures show that a number of lenders still have annual growth rates above its preferred limit of ten per cent.According to the APRA figures, ANZ's investor mortgage balance grew by 29.7 per cent over the 12 months to December, Bank Australia's by 53.8 per cent, Bank of Sydney's by 16.2 per cent, Defence Bank's by 30.1 per cent, Macquarie Bank's by 40.6 per cent, MEs by 26.8 per cent, National Australia Bank's by 53.7 per cent and Teachers Mutual Bank's by 33.3 per cent.These figures need to be read with caution because a number of lenders have revised their data over the past year, moving loans out of one category and into another.APRA's figures for overall mortgage lending show that ANZ is ahead of system with growth of 12.9 per cent over the year to December. The other three big banks have fallen below system, with Commonwealth Bank reporting growth of six per cent in its mortgage portfolio during the year, NAB 1.6 per cent and Westpac 7.1 per cent.Among smaller lenders, Bank of Queensland's mortgage book grew by nine per cent in 2015, HSBC Bank Australia's by 8.3 per cent, Bank of Sydney's by 14.4 per cent and Macquarie Bank's by 24 per cent.