As a result, there is higher risk of error in the data and the method used to produce the statistics than in other Welsh Government statistical reports.
O ganlyniad, mae risg uwch o gamgymeriad yn y data a'r dull a ddefnyddir i gynhyrchu'r ystadegau nag mewn adroddiadau ystadegol eraill gan Lywodraeth Cymru.