How are the Otakam cyclosport rankings drawn up?

Otakam rankings are based on the OTK Perf indicators (see Question/Answer on the calculation of the OTK index).
The OTK ranking is based on cyclosportives whereas the e-OTK ranking only takes into account virtual events on trainers.
The OTK rankings exist per year from 2015 and over the last 36 months. The current year’s ranking changes each time new race results are taken into account.
Sub-classifications by type of event are also proposed:
Moutain : D+/D higher than 20 (total ascent of more than 2000m for a distance of 100km)
Hilly : D+/D included in 10 and 20 (total ascent between 1000m and 2000m for a distance of 100km)
Flat: D+/D less than 10 (total ascent of less than 1000m for a distance of 100km)