Here's an example spreadsheet which will probably need some converting/love, but I've tested my current countries and it seems to be working fine. I think the information is correct.

https://docs.google.com/...Upf8-wPo/edit?usp=sharing

For some reason my population growth and loss formulas are landing +/- 1% civis off. Idk if they have been changed but my testing isn't exactly nailing pop growth on the nose. For example, I just got 372 in my country that the growth formula says I should have gotten 377 for. Donno why. I could see qz giving max pop and pop growth a small change somewhere throughout time...so feel free to make edits if I have something off. Otherwise it seems to be a totally working PCI calculator, though I'm showing your example test country needing about a 0.45 PCI correction and a 9 civilian loss on your next turn, so a few values might be a hair off, particularly max pop.