The 15 trillion is the canonical figure for the total population of the Imperium. It ought to include everyone living in the Imperium, on or off a planetary surface.I don't think that Hans's estimate is the Imperium's total budget but an estimation of the mainworld minimum budget.
Incidentally, the difference between mainworld and system population is a huge can of worms and one that I ignore when calculating individual GWPs.
Hans
 
	 ).
). ) means an average tech level of 8. That seems a bit low. The canonical average is 12. The third of the population that is unaccounted for will pull the average up, but even if almost all of them lived at TL15, they could only pull it up to a bit over 10.
) means an average tech level of 8. That seems a bit low. The canonical average is 12. The third of the population that is unaccounted for will pull the average up, but even if almost all of them lived at TL15, they could only pull it up to a bit over 10. 
 
		 
 
		 
 
		