Calculates the arithmetic mean of a set of values contained in a specified field on a query.
Avg ( expr )
The expr placeholder represents a string expression identifying the field that contains the numeric data you want to average or an expression that performs a calculation using the data in that field. Operands in expr can include the name of a table field, a constant, or a function (which can be either intrinsic or user-defined but not one of the other SQL aggregate functions).
The average calculated by Avg is the arithmetic mean (the sum of the values divided by the number of values). You could use Avg, for example, to calculate average freight cost.
The Avg function does not include any Null fields in the calculation.
You can use Avg in a query expression and in the SQL property of a QueryDef object or when creating a recordset object based on an SQL query.