A running total tells how much has piled up; a rate tells how fast it changes....

https://remote-wiki.win/index.php/How_Do_I_Convert_a_Cumulative_Total_into_an_Average_Rate_per_Hour%3F

A running total tells how much has piled up; a rate tells how fast it changes. With parcels, see why 30 boxes by noon is not the same as 5 boxes per hour. The article tracks units and time windows, so charts make sense at work.