Everyone would like to know exactly how many SMEs there are. Do you include micro enterprises in this question? In South Africa the numbers bandied about vary from 1,000,000 to 3,000,000. There is no definitive answer however. The Cipro data is badly skewed due to political interference, with numerous dormant cooperatives, closed corporations and companies. No one knows how many sole proprietorships exist in the formal sector, and even less idea of informal sector "businesses". Many cities and towns have discontinued licencing of businesses, and so no one can do a census. From a research and economic development perspective it is a nightmare. The only realistic assessment of the number of economically active businesses possibly lies at SARS, the tax man for the uninitiated. However, they have steadfastly refused to divulge this information or provide access to researchers. So much for transparent democracy, which obviously contributes to the general failure to create jobs. Researchers cannot design interventions without an insight, which we cannot get. However, there a host of other reasons that contribute to the lack of information, such as the large number of state employees with sideline businesses.
Botswana were very organised with a database of just over 13000 businesses classed as SMEs. If you assume, without any real research or statistical validity, that Botswana, Namibia and Lesotho have similar population numbers, and Swaziland approximately half that number, a fair estimate for all these countries would be 45000 SMEs. Mozambique, Zambia and Zimbabwe all have bigger populations but do not necessarily have economies that are as developed, and i would therefore hesitate to make a guess for these countries. If you assume they have double the number of businesses you would estimate 135,000 in total for the countries surrounding South Africa. But this is guesswork and not research.
However, it does help to contextualise South Africa with business numbers in the millions compared to 135,000 to say 250,000, with approximately equivalent populations of say 50 million people.
I hope this answers the reader question in this regard. However, further input would be welcome in refining this response.
I do have exact data on some countries which is available commercially.