The stun recovery for most enemy units (SECTION_STUN_RECOVERY_NORMAL) is now:
Health current : 0.06
Health : -0.09
Stun current : 0.036
For instance, if a unit has 100 health, 100 current health, 0 current stun, they would get: 6 - 9 + 0 = -3 stun recovery per turn. Therefore, they will accumulate stun until the "Stun current" offsets 2.5 stun; 2.5 / 0.036 = 69.4 so until their current stun is over 69. This value is of course higher if they're damaged in any way.
If a unit has 50 health, they will gain stun until their stun is... over 27. I should note that, if a unit with 50/50 health has 50 stun, they will never recover it and will stay stunned forever.
In L8 there was also Freshness normalized: 4.0 there, but in L9 it's currently missing.