ADL3 Effective Full Power Hours Math / Counter

I have an M130 / ADL3 / D153 and I'm trying to do something similar to engine hours, but referenced to full power.

i.e.: 1 hour at 100% throttle = 1 EFPH
2 hours at 50% throttle = 1 EFPH
5 hours at 30% throttle = 1.5 EFPH

Ideally, averaging power over a 10 second window or so and incrementing the counter, but also preserving the value until manually reset.