The MNSF for certain facilities is less than 1. Take Starports for example - I have heard from some people that the MNSF is 1 per 4 cities, and from some that it is .25 per city.
My question is: on a 1x1 asteroid, which can only have one city, will a starport make full income or only one quarter of it's full income? I think it would depend on if it is programmed to be .25 per city or 1 per 4 cities.
As for the question, no idea. I assume that it only takes into account the number of cities, but that's based on nothing more than my own delusions. I do know that they make less on planets that don't have the required number of cities, though. (a cathedral on a planet with three cities makes less than one on a planet with six cities, for example)