That number is extraordinarily high, however, I believe that it profoundly underestimates the number of children that are having difficulties paying attention, but do not meet a level that is significant enough to diagnose. When the threshold for excitement is so high, the ability and desire to concentrate on nuanced and subtle aspects of life become uninteresting and in the words of my two daughters, "annoying."
The sharpening of attention skills develops over the course of many years and essentially the brain needs to practice paying attention in order to become proficient. Research has shown that computers and computer games often conflict with the brain activities needed for the development of these "attention" skills. Too much sensory input makes it difficult to pay attention to only one activity and eventually impairs the overall ability to stay focused. It is imperative that parents encourage play that nurtures focus and attunement. You can accomplish this through choices of toys and games that you allow your child to play with, and most importantly, through the time you take to connect and attune with your child.
If you are living a fast-paced and busy life, the downtime you get from a seemingly innocuous "device" that passively entertains your kid, is probably a welcome respite. However, Gameboys, computers, cell phones and the plethora of over-stimulating toys should not be your babysitter. I am not advocating a militant, anachronistic journey back to the days of handmade wooden toys and found objects. What I am advocating is that you as parents take a conscientious look at how your child is spending his or her playtime. Make sure that all of your child's free time is not screentime. Choose toys and games that inspire creativity, artistic development, musical ability and physicality. Try to choose activities and games that motivate children to relate with each other. For babies, sometimes even simple objects like stacking cups and wooden spoons can be used imaginatively in multiple ways. For older children, think about toys that do not do "a lot" such as dolls, action figures, blocks, trains, instruments, art projects and books. Beware, you may encounter some resistance when you choose Legos rather than PlayStation, but stay the course.