There were 3,700 staff present, up from 2,800 in the previous week and 3,400 in the week before the Whitsun school holidays.
Roedd 3,700 o staff yn bresennol, i fyny o 2,800 yr wythnos flaenorol a’r 3,400 yn yr wythnos cyn y gwyliau ysgol Sulgwyn.