I'm not a programmer; I'm a freelance writer and researcher. I have a client who is looking for stats on certain "threats" to the apps market in general (not any specific app store).

One of them is cowboy coding: specifically, he wants to see numbers regarding how many apps have failed to function as intended/crashed/removed because of errors made by, in essence, sloppy coding. Note that I'm not here to debate the merits of cowboy coding, and whether or not it is sloppy.

Is there any data about this type of development?