So I'm doing some worldbuilding for a small, isolated village on the coast. The winters are harsh, but making sure everybody has enough food generally isn't an issue because they have good trade with an outside source, and they are community-led so they make sure nobody gets left out in the cold (literally or metaphorically). New people will join the town every now and again, but not often enough to really impact the population.
I think the population is small - maybe two hundred people - and the average person reaches about 65-70. So my question is, how many kids have to be born to sustain this in a zero population growth model?
I had the idea that the town tries to synchronise births so that every child has friends their own age to play with and learn from, and I thought every 8 years or so made some sense - the 8-year-olds could start learning a craft, and the 16-year-olds could teach the 8-year-olds, whilst the 24-year-olds start to couple off and have their own babies. How large would each "clutch" of babies have to be?
I did some quick maths and got maybe 20-25, but I'm not sure how accurate this is. My reasoning was 8 (number of years)/70 (average lifespan) * 200 (population) = ~22.
If anybody has a more solid idea I'd love to hear it! And if you think this is a really stupid idea then let me down gently please haha