You will always have to subtract one from a zero-based group when iterating via the number of items in the group. For example, to iterate through the Fields collection of a TableDef object based on the Count property, you need to subtract 1 from the Count property as this collection is 0-based.

However a user-defined collection is 1-based and does not require subtracting by one.

Recall that the For - Each Next structure eliminates the need of using the Count property when iterating through the items in a collection.