Ibovespa's PE is currently around 6, and if you eliminate utilities and dividend based companies, you can buy a nice basket of PE 5 Companies such as Petro and Vale.
With real interest rates at 3% a year in Brazil, PE Ratios of 20 in 2019 is the most probable scenario. That is 4 times the current value. And what about the E?
Doubling in 10 years, thanks to leverage and low interest rates, means growth with no dilution, I estimate, of 8% a year.
So to play it safe I go on the record with 600%. Compare that to US Treasuries, and you will end up with 40% max.