I am modelling the flock of sheep over a period of time.
The logic: 2023 sheep * lambing percentage = 2023 Lambs born
After one year the lambs born are added to flock of sheep. 2023 sheep + 2023 lambs
This is then multiplied by you lambing percentage to get you current year lambs births.
(2023 sheep + 2023 lambs)*lambing percentage = 2024 Lambs
And this repeats for the following years.