Price of grain (Landucci)
A dataset in Codex is a collection of facts -- whether statistical, like mortality figures or event-related like the weather -- belonging to the same subject. Datasets can be related to the historical sources they derive from, as well as to general subjects. Facts in a dataset (usually) refer to a specific time and place, hence can be plotted on both charts and maps. They often also include descriptions which turn them from being anonymous statistics into human stories.