Care should be taken in comparing the 2020-21 results with previous years since it is not clear which effects are short term because of the pandemic and which are longer term.
Dylid cymryd gofal wrth gymharu canlyniadau 2020-21 â blynyddoedd blaenorol gan nad yw'n glir pa effeithiau sy'n rhai tymor byr oherwydd y pandemig a pha rai sy'n fwy hir dymor.