This has been unchanged for three years in a row, but over the longer term the figure has been gradually falling since 2016-17, when 66% were in a stable or improving condition.
Nid yw hyn wedi newid ers tair blynedd yn olynol, ond dros yr hirdymor mae’r ffigwr wedi bod yn gostwng yn raddol ers 2016-17, pan oedd 66% mewn cyflwr sefydlog neu’n gwella.