That is a very good question.
In all honesty, I can't give you specific numbers. In my experience at the office of small and medium enterprises, the vast majority of the companies we deal with are small businesses.
Our definition of a small or medium-sized business is the one established by Statistics Canada, i.e. a business with 499 employees or less. According to statistics, the vast majority of businesses in Canada fall into this category.
Even if I can't give you an exact number, it wouldn't surprise me if the vast majority of companies involved are small or medium-sized, and rather small.