My source is also CAIN. You need to look at civilians, not all deaths:
cain.ulster.ac.uk/cgi-bin/tab2.pl
Even more stark is the percentage of deaths which are civilian, this is much more overwhelming on the loyalist side (which obviously was not targeting the security services).
Yes, ethnic cleansing is a common term but not usually in reference to the Troubles, and it was you who introduced it in this way on this thread. Hence, 'your use'.
The term originated in the Bosnian war of the 1990s, to describe the murder, expulsion and rape of hundreds of thousands of people, in an attempt to remove them from a wide swathe of territory. It is defined as 'the mass expulsion or killing of members of one ethnic or religious group in an area by those of another.' Darfur is another example, or the Rohingya today.
If you want to retroactively apply this term to the tragic but much more limited violence in the Troubles, and only to the IRA -- well, that is your interpretation. It is not a conventional interpretation. Saying the IRA committed ethnic cleansing while the loyalists only committed sectarian murders is a rather distorted view.