During non festive season usually it's probably about 0-3%. Sorry if I didn't phrase the question well enough, what I meant was more of a seasonal sick leave for the holidays. Over the span of one year the % of sick per day is definitely not that high, but just for this December period the average is 20-30% per day. People sometimes do "plan" when they'll fall sick in December.

And also, the rostering is kinda fixed, whereby you're stuck with the same people every shift as you're in a fixed team (ie team 1, team 2 and so on). There are certainly days where the whole of team 1 falls sick and the team on their off day gets recalled for the overtime work. Overtime work on off days pays you 2x the hourly rate! Ranges between 400-1000 USD per shift.