No one knows how many Rubberists are on the planet but the hundreds of manufacturers and sellers that serve the Rubberist market would suggest the number is probably surprizingly large.
Surveys by the International Association of Rubberists indicate that Rubberists tend to be well educated and reasonably successful in life. They also indicate these people tend to enjoy their fetish and do not generally regard it as an affliction.
See also: Rubber_and_PVC_fetishism.