At someone’s suggestion, I’ve just done an internet search on teachers leaving the profession. It seems to be an ongoing problem. Here is the most recent article I found on the subject:
https://www.theguardian.com/education/2017/jul/08/almost-a-quarter-of-teachers-who-have-qualified-since-2011-have-left-profession
These kind of articles have been appearing continuously for over a year.
Meanwhile more and more parents are turning to tutors:
https://au.tv.yahoo.com/sunrise/video/watch/36623550/aussie-parents-turning-to-tutors/#page1
There was a comment that remedial tutoring only works if done intensively. My approach to remedial tutoring is to focus on one thing at a time and help the student learn that fundamental step even if it means going back to things they were meant to learn two or three years ago and make sure they learn it properly once and for all. This won’t have the effect of improving their grade immediately, but it will have the lasting benefit of providing them with a solid foundation on which they can build further learning.