English to Spanish Tech/Engineering Engineering (general)

Hey!

I'm translating a technical engineering document which reads as follows:
"where a specific system for collection and destruction of methane is mandated by regulatory or contractual requirements or is undertaken for other reasons, the ratio of the destruction efficiency of the baseline system to the destruction efficiency of the system used in the project activity shall be used".

Even though I can't seem to find the right translation for "ratio" in this context, the whole paragraph has given me some gray hairs. Here's my attempt (and feel free to make any other corrections - greatly appreciated):
"donde quiera que se exija un sistema específico de recolección y destrucción de metano como requisito regulatorio o contractual, o se construya por otras razones, debe utilizarse el coeficiente de la eficiencia de destrucción del sistema inicial y la eficiencia de destrucción del sistema utilizado en la actividad el proyecto"

Thanks so much!