Code vs Zombies, question on score computation

Hi ,
The instructions states:
Scoring works as follows:

  1. A zombie is worth the number of humans still alive squared x10, not including Ash.

Does this mean that when you kill a zombie, the score takes in account the number of humans that are alive in that moment or is the number of humans still alive at the end of the game (that is squared+multiplied with)?

Thank you in advance for any clarification.
Regards