We published the first estimate on 19 February 2021, published the second estimate on 19 March 2021 and the third estimate on 29 April 2021.
Fe wnaethom gyhoeddi’r amcangyfrif cyntaf ar 19 Chwefror 2021, yr ail amcangyfrif ar 19 Mawrth 2021 a'r trydydd amcangyfrif ar 29 Ebrill 2021.