No changes. Usually, at a point, workers start to decease for the first time. Once the death spiral starts, it can be devastating but it eventually meets a balance point.
This topic might be helpful:
viewtopic.php?f=12&t=4481If you watch the second video there, we start the simulation with 30M workers and 0 health. 10 days later, the population drops at 20M where it stabilizes. Then slowly it crawls up to 25M. The drop from 30M to 20M is the death spiral I am talking about. There is a way to slow down the death spiral once it starts; you can reduce workload or bring more immigrants. But perhaps it is better to let it balance based on the terms you are willing to provide.
If you watch the first video, the same setup brought the population in 26M at the end of the 365 days experiment. This is how it goes. After work, sometime the population breaks and the spiral begins.
And we are talking about a developed plantation here. If yours is undeveloped, then effects will be worse.