Rio De Janeiro is a city that located in s city has a medium to high businesse and tourism number, around 200-400. It's not recommend to use this city as your main hub.
Creating a long distance routes (Singapore-Rio de Janeiro) is not recommended due the distance is too long and you can get only 60-80% occupancy. creating a passengers to and from the high productivity level city like New York, Los Angeles, etc with 747, 777, 787, and other airplanes except A380, will get 90%-100% occupancy.
Caution! When economy crisis is occurred the business and tourism number sometimes drop around 100-200.