Within the Greek and wider Balkan anchor set, yes — your regional shares are normalized to 100% of the Greek-and-Balkan-assigned portion of your DNA.
If you carry a lot of ancestry from outside this region — significant Western European, Eastern European, Levantine, or African ancestry, for example — then the overall slice of your genome assigned to the Greek-and-Balkan set may be smaller. The breakdown only describes that Greek and Balkan component.