• Aggregate periodic archival-program metrics into count, total, arithmetic mean, minimum, and maximum for annual reporting.
• Apply the same explicit rule consistently during ingest, quality control, reporting, or preservation planning.
• Expose records that need human review without silently rewriting the source data.

The mean weights every supplied period equally; monthly and quarterly values must not be mixed without prior normalization.^[1]

• Totals are meaningful only for additive metrics measured in the same unit and covering non-overlapping periods.
• Preserve the original value and record the rule version when using this result in an archival workflow.

• Email Archive Message Count per Account Summator

  Use Email Archive Message Count per Account Summator to sum exact nonnegative per-account email counts and report account count, total messages, and arithmetic mean. Choose this tool when you need to aggregate periodic archival-program metrics into count, total, arithmetic mean, minimum, and maximum for annual reporting.

• Born-Digital Disk Image Size TB Aggregator

  Use Born-Digital Disk Image Size TB Aggregator to aggregate nonnegative disk-image sizes into image count, total terabytes, and average terabytes per image. Choose this tool when you need to aggregate periodic archival-program metrics into count, total, arithmetic mean, minimum, and maximum for annual reporting.

• Email Archive Message Count per Account Summator

  Sum per-account email message counts across an archived mailbox corpus and report the account total and mean messages per account.

• Born-Digital Disk Image Size TB Aggregator

  Aggregate born-digital disk image accession sizes in terabytes into a count, storage total and mean image footprint.

• Reference Statistics Monthly Question Count Trend Percent Calculator

  Compute the month-over-month percent trend in archival reference desk question counts with the absolute change and its direction.