We published the first estimate on 29 April 2021, published the second estimate on 21 May 2021 and the third estimate on 25 June 2021.
Fe wnaethom gyhoeddi’r amcangyfrif cyntaf ar 29 Ebrill 2021, yr ail amcangyfrif ar 21 Mai 2021 a'r trydydd amcangyfrif ar 25 Mehefin 2021.