This however need to be dynamic. So, for instance, the user selects the 12/31/2019 period and enters the related value for the period. For the next period 3/31/2020, they need enter the related value for that period. Keep in mind that the historical periods values need remain captured.

That is correct. Is this possible? or do you have a better suggestion in order to manage and track data for this type of scenario within SharePoint?