Maintain Relationships if it is changes

Hi Team

We set Relationships like below process
Division > Sub-Div > Plant

For year : 2018 the data like below

DivisionSub-DivPlantItem
D1SD1P1001


after a year the relationships is changes

 

DivisionSub-DivPlantItem
D1SD1P2001

The Plant is changes for Year : 2019

The question is, If I change the Relationships by the Year 2019, then how I can track data for Year 2018?
Please advice
Best Regards

Answers