Answer:
There is no comprehensive study, or compiled data to support a definitive answer to this question since Martial Art systems, schools, and practitioners are constantly growing and changing. Even the very definition of what a Martial Art is has evolved in recent times. It is difficult for experts to agree, and the world is filled with novice practitioners who define things very differently.
Speaking to the nature of unarmed combat Martial Art systems, some of the more predominant countries have been China, Korea, Japan, Philippines, United States, Canada, and the United Kingdom. Often times, in Asian countries, the Martial Art is a part of their heritage and culture, and is shared openly on a basic level, but those that pursue it to mastery might be less than non-Asian countries. In many Asian countries, service on the police force, or in the military is mandatory for all adult males, and the Martial Art is part of that training In many other countries, hand-to-hand combat in the military serves as an introduction to Martial Art, but again, it does not necessarily lead to a serious study, or mastery of the art.