During 2020-21, this proportion dropped suddenly, which could be due to the coronavirus (COVID-19) pandemic, as an opposite trend can be observed for those giving 'other' reasons.
Yn 2020-21, cwympodd y gyfran hon yn sydyn, efallai oherwydd pandemig y coronafeirws (COVID-19), gan y gellir gweld tuedd fel arall ymhlith y rheini sy’n rhoi rhesymau ‘eraill’.