No real battles, no gains or losses, just pointless bleeding
Doubtlessly the rebel combat losses are in the similar range. Based on the first six months we are then again looking at some 450 KIA for 2017 from both sides.
Additionally in 2016 the Ukrainian army lost another 256 soldiers outside combat -- mainly due to illnesses (58), weapons accidents (39), murders (30), and a suicide epidemic (63).
The rebels too likely suffered some deaths outside combat though their numbers should be lower, since albeit similarly lawless (recall the many rebel-on-rebel assassinations) they have higher morale than Ukrainian soldiers fighting far from their homes, and have far fewer men under arms overall.
The UN reported 23 civilian deaths from 16 November 2016 to 15 February 2017 and 36 civilian deaths from February 15 and May 15. At this rate there will be some 120 civilians deaths again this year.
Added all together the war in Donbass is en route to produce another 900 deaths this year (450 KIA, 120 civilians, 300 soldiers outside combat). A hell of a death toll for what is supposed to be frozen war without real battles and is completely out of the headlines.