Complex sentence: Covering an area of with an overall population of, "Epirus and Western Macedonia" is medium-sized, yet one of the least populated of the seven decentralized administrations in Greece, second only to the Decentralized Administration of the Aegean.
Split into simpler sentences: Covering an area of "Epirus and Western Macedonia" is medium-sized by area. With an overall population of, it is however one of the least populated of the seven decentralized administrations in Greece, second only to the Decentralized Administration of the Aegean.