I think this KPI is still pretty vague, so my suggestion is to run a retrospective towards the end of Season 1 - and see what lessons are needed to be learnt, as well as how you might better contextualize this in future seasons.
Throughout the course of S1, both myself and @vorcigernix (as part of the OKRs Initiative) will be checking in at intervals, to see how much progress is being made on reaching set KPIs, see how we can offer support etc. I imagine this can be better defined, as time goes on.