and that 1% would probably represent terraform-able planets/ moons. its much more likely that many stars have planets but most are completely unable to support anything close to life.
if the above numbers are ~about~ right, then we could average, say, 42.5 ships per sector? with 1mil. sectors, that's a good deal of ships (of course with more constantly on the way).
Well, we kinda assumed that no more than half of the sectors are actually under imperial control, as the IN won't go into the halo, and there are a few solid holdouts/warpstorms where other races/factions exist.
Some sectors may be completely empty, like areas inbetween the galactic arms.
The gothic sector has ~50 habitable planets, meaning they aren't unihabited, penal colony, or mining world.
The Calixis sector has nearly 100. I think the number is closer to 5% of planets are habitable, or systems with planets have an average of 5 planets/moons (which is much more likely)