Hmm
I wouldn't want to do a job which was just cover - i.e. 20 lessons of cover a week, plus running round sorting out the problems - it's just not rewarding enough.
Also, financially, if staff are prepared to do that amount of cover for the pay they get, there is no incentive for schools to use supply staff ever! Our supply staff do 5 covers a day, or 25 a week: that's one of the reasons they are paid more than us. (Repeatedly we have staff requesting that we/I cover lessons rather than supply staff, which is encouraging, but it doesn't mean I'm prepared to do 5 a day.)
Initially our school envisaged us doing more, and for the first term I was averaging 19 covers a week, but it just wasn't working out: you just end up lurching from one crisis to another sometimes!
Now that we generally do 3 covers a day, we also have time to sort out any problems and follow up any issues and have time to support our departments in admin roles and so on.
Our school has a heavy week next week as there is a ski trip out, which involves about 4 members of full-time teaching staff (plus some others). But that won't impact significantly on my role: I will still do around 15, and we will use supply staff to pick up the slack.
Have you analysed the 98 covers? Are they all illness? Or are there meetings and courses and so on. One thing our school has had to do, and others have as well, is to become stricter on the procedures for requesting cover.
In the past in some schools there was:
'legitimate cover' - you were ill or on a course,
and then there was 'other cover' - you wanted to go and see your dd in school play, or you had to see a parent.
The former was covered by an official cover system, but the latter was usually done on a tit-for-tat informal basis with colleagues in your department.
With the advent of CS in some schools the second category rapidly moves into the first category, especially if the introduction of CS also coincides with cover requests being handled by a far less senior member of staff. And before you know it the whole system has spiralled out of control and everyone is requesting cover left, right and centre for all sorts of spurious reasons.
How does it function at your place re setting work? Who provides the work for the cover lessons and how does it get to the classroom?