This is one of the most consistent trends we've seen in all the decor publications! (stylemutthome.com)
As you can see in the chart below, this has been a very consistent trend, too. (sportsinsights.com)
But it does seem to comport with a recent meta - analysis of global and U.S. voucher initiatives, by Shakeel, Anderson, and Wolf, showing a prevalent and consistent trend toward early dips in performance followed by year - three and year - four positive effects, in both literacy and mathematics. (educationnext.org)