Info needed: sales of mid-sized companies in SP (São Paulo)

I am helping a friend writing a business plan (for free) for an innovative service solution for mid-sized companies with a certain business complexity here in Brazil. I an NOT thinking about "mom-and-pop" stores, restaurants or liberal professions (like doctors, lawyers). I am thinking about mid-sized companies with sales between 3 and 20 mio Reais per year, but also larger companies who keep an external accountant for one reason or another. I would like to get a feeling for the size and growth of overall sales of such companies.

Does anyone have statistics or any idea about this with regard to the state of São Paulo and in Brazil overall? Thanks for any help in this matter. I have checked the SEBRAE page but did not find what I am looking for there.