Does anyone happen to know what the level of indigenous Afghan government revenue was around 1989-1992 with and without direct Soviet aid?

My personal experience in Afghanistan is limited to only 3 months so far in two trips.

Based on the current environment and likely future environment here in Afghanistan I have can't help but narrow down the Soviet experience here to the event approximately 3 months before the fall of the Afghan regime in April 1992.....which was the cut in aid with the fall of the Soviet Union.

The recent publishing of the book Black April:

It covers the South Vietnamese regime between 73-75 and has me focused on the point where the US Congress slashed aid in a couple tranches and South Vietnam fell approximately 6 months after.

I'm sure there are heaps of other factors that contributed to the fall of both respective regimes, but I can't help but wonder how current Afghanistan will survive in a recognizable form when approximately $16 billion is being spent annually, but only about 10% of that total spend is legitimate government revenue.

With ISAF quickly heading for the exit, international funding levels likely to shrivel quickly from short public attention spans and increasing pressure from the next couple of waves of the perpetual global financial crisis, I reckon it's a near guarantee the Afghan economy could suffer a significant contraction in total spending in the order of 30-50%(my amateur guess), possibly more.

I wonder if anyone has done any open source Afghan economic modeling for 2014-17 with and without foreign aid?

It would be interesting to compare 2014-17 Afghan economic modeling with historical data from 1989-92.