Teacher absenteeism

Would really love to get an idea of how many lessons are missed by teachers being unavailable for class. Is it possible to get this data?

Am slightly horrified by how many 'free periods' my second year son has. Probably missing a class per day on average.

I do not think this is a problem limited to one school.
I suspect the teachers may be in the school some of the time but covering for 'more important' classes.
I know they are stretched, but don't have the exact info as to whether there are open, unfilled roles or high rates of non-attendance.

I ignored the issue last year as figured 1st year was the least important, but it's not showing any signs of slowing, with CBAs coming up I am worried about the material being missed.

When other teachers do cover the class it tends to be a crappy worksheet or 'catch up on your other homework' hour. It is affecting both examined and non-examined subjects.

This was not something I saw happening in even the worst schools 30 years ago.

The school are defensive about every enquiry and as I am sure this is out of their control, I do not expect to get any answers from them. Are there statistics going up to dept of education? Would like to lobby my TD about this, but only have anecdotal data.