We published the first estimate on 22 November 2019, published the second estimate on 20 December 2019 and the third estimate on 30 January 2020.
Fe wnaethom gyhoeddi’r amcangyfrif cyntaf ar 22 Tachwedd 2019, yr ail amcangyfrif ar 20 Rhagfyr 2019 a'r trydydd amcangyfrif ar 30 Ionawr 2020.