We published the first estimate on 20 August 2021, published the second estimate on 24 September 2021 and the third estimate on 28 October 2021.
Fe wnaethom gyhoeddi’r amcangyfrif cyntaf ar 20 Awst 2021, yr ail amcangyfrif ar 24 Medi 2021 a'r trydydd amcangyfrif ar 28 Hydref 2021.