Missing server info w/ zero jobs

When running a report with an external source (.csv file) and a server doesn't have any reported jobs for the selected time window, DPA doesn't include that server in the report at all.  Is this because the field from the csv file doesn't have anything to attach itself too?  I've specified that any empty field be a "0", yet it's as if the server doesn't exist and isn't being reported on at all.