You don't say what province you are in so that makes a difference as children start school at different ages in different areas.

One of the things that causes the turnover for us is that most children start care at a year old and if mom has a second baby and goes on maternity leave they may remove the older child totally or want them to move to just a couple days a week. That means that you may only have a child for a year before the maternity leave starts. Then if the family returns after the maternity leave it is only a year until the older child starts school. So yes we do a lot of transitioning new children, spend a lot of time in the infant/toddler catagory for programming. As well many children leave home care and move to a daycare centre/ montessori or a similar nursery school program by age 3-4.

I would totally prepare your setup to deal with the really little ones and then home to keep them as long as you can.