Complex sentence: Of this area, 66.9% is used for agricultural purposes, 25.2% is forested, 7.4% is settled (buildings or roads) and the remainder (0.5%) is non-productive (rivers, glaciers or mountains).
Split into simpler sentences: Of this area, 66.9% is used for agricultural purposes, while 25.2% is forested. Of the rest of the land, 7.4% is settled (buildings or roads) and the remainder (0.5%) is non-productive (rivers, glaciers or mountains).