Also, where did you get the number 1.5k from?
That figure was corrected a number of months back to 1.2k was it not. The most accurate figure I've seen stated is 11,600, although it doesn't seem to be in widespread use, although the 1,200 figure is often caveated.
The total isn't all civilians. No official figures have been released on the split is my understanding.
It's also not clear how many are attributable to Israel's response, but it's clearly non-zero and may well be a significant proportion.