I should have looked up that number because there is really good data on that. The main thing has to do with literacy. What's often not recognized is that in the prevention of literacy delay in school, the time to prevent that is in the preschool area. The predictors of a child's not learning to read are deficits in language skills, speech perception skills and speech production skills, and what's called “emergent literacy”. All of that is happening between the ages of 3 and 5.
If a child starts school and their speech and language skills are not within normal limits at that point, at age 5 and age 6, there's then a heightened risk of a whole bunch of bad outcomes. These include their being bullied at school, social and emotional problems, conduct disorders, ADHD—anxiety disorders in girls skyrocket—and not learning to read. There's about a 60% probability that the child will have a reading disability in grade 3. Then the chance of school failure increases the probability of boys—not girls, but boys—coming into contact with the justice system and so on.
The early intervention is absolutely essential and we are really falling down on that.