Totals add up what has happened; rates show how fast it happens. For parcels,...

https://activecalculus.org/author/Running-Totals-Rates-of-Change

Totals add up what has happened; rates show how fast it happens. For parcels, 120 by Friday is a total, while 30 a day is a rate. Check the units and time window before comparing them, and you’ll know what a chart is really saying.