Calculating difference between previous and current readings
I need to calculate the difference between the current and previous readings for a tenant's utility use at their site. I am new to FM Pro and have no idea how to go about doing this. I have attached a copy of my relationships graph to assist. I need to display the result on my tenants layout. I already have a portal on the tenants layout which shows the readings by date order, filtered for that tenant.
Any assistance would be greatly appreciated.