. Most children will complete the reading scheme and move onto free readers during Y3.
You either teach or have your children at a very high achieving school if the majority of children are on school-issued free readers in Year 3. In my experience it is a rare child who is at that stage so young (remember the reading age of the top levels is around 13) and I would say the average child in schools I have experience of moves somewhere in Y5 or even Y6. There are some who go earlier and some who never get there. Of course, whether they actually read the school issue books, scheme or no, is another matter, and there is nothing to stop them reading 'freely' out of school, whatever 'level' they are on.