Nielson’s 2014 summit offered statistics gathered for the previous 4 years in children’s/YA publishing. In addition to posting growth all those years, the categories that performed the best were YA and middle-grade books (also called chapter books).
2014 was reported to be the “best year ever” for the C/YA category. Last year, 17 of the 20 top-performing books were C/YA. A full 35% of the market for physical books is in this category for US sales.