In 1931 the Rottweiler was officially recognised by the American Kennel Club. In 1936, Rottweilers were exhibited in Britain at Crufts. In 1966, a separate register was opened for the breed. In fact, in the mid-1990s, the popularity of the Rottweiler reached an all-time high with it being the most registered dog by the American Kennel Club. In 2017, the American Kennel Club ranked the Rottweiler as the eighth-most popular pure-breed in the United States. The skull is of medium length, relatively broad between the ears. The forehead line is moderately arched as seen from the side, with the occipital bone well developed without being conspicuous. When seen from the front, the front legs are straight and not placed close to each other. The forearm, seen from the side, stands straight and vertical.