On this measure Wales, according to the most recent data (2018), is at 81% of the UK figure, having fallen from 88% at its peak in 2003.
O ran y mesur hwn, mae Cymru, yn ôl y data diweddaraf (2018), ar 81% o ffigur y DU, ar ôl gostwng o 88% pan oedd y ffigur uchaf yn 2003.