The IMF has had a go at working this out, in a paper published earlier this year. The results are expressed cautiously, surrounded by references to uncertainty, but suggest that the Tanzanian government could be looking at a peak of US$5-6bn revenue each year between 2029 and 2044. Given that for the past few years, official aid to Tanzania has ranged between $2-3bn annually, and the total tax revenue in the 2014/15 Tanzanian government budget is just over $6bn, we‘re talking potentially a lot of money