One possible reason is that many higher transactions were also brought forward into June 2021, for example as part of chains which included those main rate transactions brought forward.
Un rheswm posibl yw bod llawer o drafodiadau uwch hefyd wedi’u symud ymlaen i fis Mehefin 2021, er enghraifft fel rhan o gadwyni a oedd yn cynnwys y trafodiadau prif gyfradd hynny a symudwyd ymlaen.