Deaf people in Bishkek

No this post is not about me personally. But, I do prefer the term deaf or more accurately partially deaf to hearing impaired. Rather this post is about the fact that I have seen more people talking in sign language in Bishkek than in any other city I have ever visited. I see people communicating in sign language here almost daily. It seems to me there must be some reason why Bishkek has such a high percentage of deaf people. If anybody has any information regarding this matter I would really appreciate it if you left a comment.