Show subtracted value on Trend with InfluxDB

Dear Grafana Experts,

I hope you are all good.
I have here a power meter that measures energy consumption that accumulates over time, so for example my value changing every minute.
12:00 - > 50 mwH
12:01 -> 60 mwH
12:02 - > 70 mwH
12:03 -> 80 mwH
so on and so forth.

What I want is to view a Trend graph where it shows the power consumption for the specific period of time instead of its spot/accumulated value, so the 12:00 to 12:01, in the above example @timestamp 12:00 my value should be 10 (60 minus 50), I can’t see any functions to do what I want, I hope someone can help me.

Thank you.

With kind regards,
Henjoe