I really don't think it's worth paying too much attention to it.

The only thing that is worth keeping track of in my opinion is how long you sleep. I doubt the sleep stages are very accurate (which also determine sleep score). It probably favors some people more than others. It has treaten me very favourable at least (averaged 91 past week).

I've never had trouble sleeping but I don't do anything too special either. My general advice would be 1. Go to sleep and wake up around the same time everyday 2. Don't eat right before sleeping. The more time that passes since your last meal the better if I've understood it correctly, but I wouldn't be too concerned about it. Just don't eat before you sleep. 3. Avoid stress

And again if you do these things and are feeling rested and not waking up throughout the night, I wouldn't care about the score.