In spite of the vast expenditure and research on the process of learning to read, there is little if any evidence that the incidence of reading disability is declining. Some, in fact, would argue that the contrary is true.
Braun, C. (1981). Obstacles to Reading Acquisition: Preventative and Corrective Concerns. Reading Horizons: A Journal of Literacy and Language Arts, 21 (2). Retrieved from https://scholarworks.wmich.edu/reading_horizons/vol21/iss2/2