Financial regulators' efforts to rein in high-risk mortgage lending over the past year have been largely successful. The Australian Prudential Regulation Authority's latest report on ADI property exposures shows that growth in investment lending slowed, the proportion of high loan-to-valuation ratio loans was down and low-doc lending declined.The only trend the regulators would not like was the increase in the proportion of interest-only loans in new mortgage lending last year.APRA's loan approval data is based on authorised deposit-taking institutions with more than A$1 billion of residential term loans on the books. Those lenders approved $371.8 of new mortgages in 2015 - an increase of 10.2 per cent over 2014.There was a 14.2 per cent increase in owner-occupied loans, which made up 63 per cent of all new loan approvals.Investment loan approvals rose 4.1 per cent and made up 37 per cent of new loans.The proportion of new loans with high loan-to-valuation ratios fell during the year; $52.6 billion of new loans (14.1 per cent of the total) had LVRs between 80 per cent and 90 per cent. This was a reduction of $886.7 million (1.7 per cent) from the previous year.And $36.9 billion of new loans had LVRs above 90 per cent, making up 9.9 per cent of total new mortgage lending. This was a reduction of $4 billion (9.8 per cent) from the previous year.The proportion of interest-only loans rose. $155 billion of new loans (41.7 per cent of the total) were interest-only. This was an increase of 8.3 per cent from the previous year.Low-doc mortgage lending declined. The value of outstanding low-doc mortgages fell from $32.3 billion in December 2014 to $26.9 billion in December last year.Total outstanding ADI residential term loans to households were worth $1.4 trillion at the end of 2015. This was an increase of $112.6 billion (8.9 per cent), compared with December 2014.Owner-occupied loans made up 63.9 per cent of the total, increasing by $100.1 billion (12.8 per cent) during the 2015.Investor loans made up 36.1 per cent of the total, increasing by $12.5 billion (2.6 per cent) during the year.