Westpac, the principal industry perp regarding 'easy to obtain' and (in APRA's view) oversupplied interest-only loans has reduced the flow sharply, the bank's June 2017 quarterly update shows.Applications for interest-only loans were "36 per cent of flow", the bank said, down from 47 per cent in the March quarter. Westpac said the flow of funded IO loans fell to 44 per cent from 52 per cent of all home loans over the quarter. This compares with 50 per cent across the half year to March 2017.The bank said it was "on track to have the flow of interest only lending below 30 per cent by September 2007", as APRA expects.Sharing data on a second metric under close APRA watch, Westpac said its growth in investor lending "using the APRA definition" was 5.9 per cent - this is 1.3 percentage points lower than the growth in this segment based on analysis of APRA's monthly banking statistics.The bank's CET1 capital ratio held steady at 10.0 per cent over the quarter.