[2]Mae cymariaethau â phum mlynedd yn ôl wedi cael eu gwneud yn erbyn yr ystadegau swyddogol ar gyfer y cyfnod, yn hytrach na gwybodaeth reoli’r GIG ei hun. Mae gan wybodaeth reoli’r GIG cyn 2018-19 nifer uchel o gofnodion nad ydynt yn nodi oedran. Gan fod gwahaniaethau rhwng yr wybodaeth reoli a’r ystadegau swyddogol, mae’n bosibl bod y newid, mewn gwirionedd,yn wahanol i’r 8.6% a nodir.
[2]Comparisons with 5 years ago have been made against the official statistics for the period rather than NHS management information. NHS management information prior to 2018/19 has a high number of records with no age specified. As the management information and official statistics differ, the actual change could be different to the 8.6% shown.