This is because of higher rate refunds being paid out in each month (for higher rates residential transactions which were effective in earlier periods, back to April 2018).
Hyd yma bu mwy o adferiad o ran trafodiadau preswyl cyfraddau uwch nag ar gyfer pob trafodiad preswyl, er fel y dywedwyd eisoes, mae hyn wedi gwastadu rhywfaint yn y chwarter diweddaraf.