Vanishing Student Blues

Ok - we are now at day 22. I started with 20 students on day 1. On day 3 I lost a student. On day 9 I lost another student. Day 10 I lost yet another. On day 12 I gained a student and on day 15 I gained another. Today I lost my student from day 12! I am at 18 now and have already lost 4 kids. This is too many too fast. How are teachers ever supposed to be able to make an impact with a revolving door? More importantly, how will kids who move ever have the opportunity to learn?