It's my understanding that players with lower end computers might see less population count. Those with higher end computers may see larger population count. The overall population count depends on what your computer can handle.
Demographic information may be different depending on if you've played the save or not, added Sim families, and/or if you have any kind of story progression on. Regardless if it's EA SP or Nraas SP.
To check the demographics in a save file you need
Nraas MasterController and use the path below:
Using an active Sim click on City Hall > Master Controller > Demographics > (Town) Population - X to dismiss the filter to get the information.
Starting a new game, tourists maybe added to the count in the town. You can turn off tourists via Nraas.
Using an active Sim > Click on City Hall > Register > Tourists - Set Allow Tourists to False (set to True by default)
If using Nraas SP, please visit it's page
here for more information on how to use it.
If your game has a big population and you want to fix that, you can remove some Sims with Total Annihilation - Using an active Sim click on City Hall > Master Controller > Town > Total Annihilation - X to dismiss the filter to get to the list of Sims. Wait for it to fully load and select what Sims you'd like to delete.
** This will delete the Sims as if they never existed in your save file.
I'm sure there are other ways to control the population of the town. That's just the one I know of.
A Tip from Trip, about population demographics in the post linked below:
Re: Recommended number of sims per world?
https://www.carls-sims-4-guide.com/forum/index.php?topic=32172.msg510927#msg510927Adding these tips about Sims 3 culling Sims.
--Inactive Sims and families get culled essentially at random whenever the game feels it needs to balance the population. The reasoning behind this "balancing" seems somewhat nebulous.
Story progression will not touch sims who used to live in your household after they move out.
