Does the Sleep spell use current or maximum hit points?

Question

On Page 101 of the D&D 5e Basic PDF the effect of a Sleep Spell is stated as follows.

This spell sends creatures into a magical slumber. Roll 5d8; the total is how many hit points of creatures this spell can affect. Creatures within 20 feet of a point you choose within range are affected in ascending order of their current hit points (ignoring unconscious creatures).

Does hit points of creature refer to their current hit points or their maximum hit points.

Maximum hit points are defined as the number of hit point a undamaged creature or character has. Note page 10 of the D&D 5e Basic PDF.

Each time you gain a level, you gain 1 additional Hit Die. Roll that Hit Die, add your Constitution modifier to the roll, and add the total to your hit point maximum.

Answer 1

It's current hit points. It says so in the last sentence.

Creatures within 20 feet of a point you choose wthin range are affect in ascending order of their current hit points (ignoring unconscious creatures).

I added that emphasis. So if you roll a 5 (a very unlikely roll), you affect a creature or group of creatures with 5 current hit points or less, starting with the weakest. Once the total current HP of the affect creatures is 5 or more, you don't affect anything else.

If it were total hit points, this spell would be more-or-less useless.

Answer 2

It would seem logical that the spell affects the creatures in view of their current hit points. The first quote you've used even seems to say so: in ascending order of their current hit points -- and this is further supported by the addition of ignoring unconscious creatures, because why would the spell ignore them if it was their maximum hit points that mattered instead of their current one? :)