Besides all those colonials, there are about 50 million Imperials, including some who live and work in the colonies outside Imperial jurisdiction and some people who are permanent residents of Imperial Direct Jurisdiction but are not (or not yet, or no longer) in the Service.
I haven’t worked out the demography properly, but I suppose that of the 50 million Imperials fully 34 million are Imperial servants, the rest being (a) dependent children of iImperial servants, (b) retired former Imperial servants living in IDJ (many retire to a colony instead — their homeworld, somewhere they worked and loved, somewhere where their pension will go further…), and © natives of IDJ with birthright residency employed by the small private sector and not the Service.
As a rough hack I suppose that
- 5% of Imperial servants work at the capital, in the New Capitol, the Palace (Old Capitol), or otherwise at Sol. That’s 1.7 million.
- 19.4% of Imperial servants work at sector HQs, or are stationed there as deployable reserves. That’s an average of 322 thousand at each of the twenty SHQs.
- 75.6% of Imperial servants are deployed to colonies, living and working either in the Imperial enclave (which is part of IDJ), in Imperial orbital habitats, or at project stations, field offices &c. &c. out in colonial jurisdiction. That’s an average of 22 thousand in each solar system.
Further, I suppose that the non-servant portion of the Imperial population is more concentrated than that because
- Retired Imperial servants living in colonial jurisdiction aren’t included in the count.
- Natives of IDJ who aren’t Imperial servants aren’t included in the count if they live and work outside IDJ.
- Imperial servants living and working in the field tend to put off their child-bearing until they get a less remote posting, and if they do have children tend to leave the kids in Imperial boarding-schools. There are schools in most enclaves, but those at SHQ and (more so) Sol are more prestigious, sometimes better or more specialised, in some ways safer, and offer better stability and continuity for the children of parents whose work is peripatetic or involved short postings to different worlds.
There are kids, retired folk, and free lances in Imperial enclaves, but fewer in proportion than the average, and virtually none out in colonial jurisdiction.
- There are 1.6 million retired Imperial servants, dependants of Imperial servants, Imperial cadets at universities and academies, and free-lancers with residency in IDJ living at Sol.
- There is an average of 180 thousand retired Imperial servants, dependants of Imperial servants, Imperial cadets at universities and academies, and free-lancers with residence in IDJ living at or around each SHQ.
- There is an average of 6.2 thousand retired Imperial servants, dependants of Imperial servants, and free-lancers with residency in IDJ living in each system in the Imperial enclave and Imperial orbital facilities.
Result! The Imperial population of
- Sol, including the Capitol, is 3.3 million
- the average SHQ is 502 thousand
- the average colony and its spatial environs is 28.3 thousand.