* December 2016 Istanbul car bombing / suicide bombing near a football stadium, killing 44 people
* October 2016 Istanbul bombing - injuring 10 civilians
* June 2016 Istanbul bombing / killing 6 civilians
* March 2016 Ankara car bombing killing 37 people
* June 2006 Manavgat (in the province Antalya, a popular region for tourists) detonation of a bomb in a tourist site, killing four people
Sources:
https://en.wikipedia.org/wiki/October_2016_Istanbul_bombing
TAK != PKK, TAK claimed responsibility. 39 of those killed were police officers. Turkish military also kills civilians while targeting opposing militia groups.
> * June 2014 Istanbul bombing / killing 6 civilians
Link? Did this happen?
> March 2016 Ankara car bombing
TAK not PKK, again.
> * June 2006 Manavgat
Yet again, TAK.
> https://en.wikipedia.org/wiki/October_2016_Istanbul_bombing
Not intentional targeting civilians, accidental premature explosion of bomb. Only one of the attacks you've mentioned that was by the actual PKK and actually killed civilians.
Source on PKK targeting non-paramilitary/police/military civilians in the last 20 years?
e: I can find this from 1987 (a time when the Turkish state was also actively involved in massacring civilians) https://en.wikipedia.org/wiki/P%C4%B1narc%C4%B1k_massacre