Based on 2013 American Kennel Club statistics, Boxers held steady as the seventh-most popular breed of dog in the United States for the fourth consecutive year. However, according to the AKC's website, the boxer is now the eleventh-most popular dog breed in the United States. A line of naturally short-tailed (bobtail) Boxers was developed in the United Kingdom in anticipation of a tail docking ban there; after several generations of controlled breeding, these dogs were accepted in the Kennel Club (UK) registry in 1998, and today representatives of the bobtail line can be found in many countries around the world. Like fair-skinned humans, white Boxers have a higher risk of sunburn and associated skin cancers than colored Boxers. The extreme piebald gene, which is responsible for white markings in Boxers, is linked to congenital sensorineural deafness in dogs. It is estimated that about 18% of white Boxers are deaf in one or both ears, though Boxer rescue organizations see about double that number.In the past, breeders often euthanized white puppies at birth.