If a data field is specified as being average, then data is accumulated up the database structure and in totals using a numeric average. This means that the data field values from each of the component records are added together, and then the sum is divided by the number of component records. The following example of a branch of database structure illustrates how an average data field is accumulated for an upper level record.

An example of an average type data field is "Number of Coal Plies". Average field types may also be useful in a calendar or report database (with year and month as the levels), where you want to report the average monthly target tonnage for a particular year. Other data fields are sometimes assigned as average type when they should really be weight average, but there is no other appropriate data field to weight them against. Care should be taken when this occurs as the average result will not be strictly correct, however it may be useful as a guide.

Zero values may or may not be included in the determination of the average value, by selecting or deselecting the Include Zeros box on the Field Type screen.