It doesnt have to be large amounts of complete non attendance. Regular attendance is defined as attending for more than 90 per cent of the term. Terms are about 10 weeks so 50 days, to be counted in the non attendance figures you have to miss five days in a term. A couple of illnesses can easily knock kids under that, not that there aren't more long term absences for other reasons as well.
On illness, term 2 2022 is the middle of our biggest covid outbreak when omicron got in and all the rules were being relaxed. Attendance has gone up again since then but is still lower than pre covid. Seems cynical that Seymour would pick this period as the end point when these stats were being collected until term 3 last year.