The report counts actions taken during the reporting period. The approvals and denials issued in a given year are largely decisions on petitions filed in earlier periods — USCIS's own notes caution that some applications approved, denied, or pending a decision "may have been received in previous reporting periods." The approvals in one column and the receipts in another are not the same petitions.
The same file makes the point vividly. On the labor-certification-based E21 line in FY2025, USCIS recorded 52,795 approvals against 49,921 receipts — more approvals than filings that year, because it was working down a backlog. A period ratio can exceed anything a filing cohort could produce. It is a throughput measurement, not an outcome probability.
Two further limits. The denominator includes only decisions: withdrawals, administrative closures, and transfers are absent, and USCIS says so — "Some actions taken on cases are not reflected in this report such as administrative closures and transfers between offices." And the counts are vintage-dependent, since "[c]ounts may differ from previous periods due to system updates and post adjudicative outcomes."
One more calculation to watch for. Articles reporting an NIW approval rate in the low forties for FY2024 are dividing approvals by receipts — 27,526 by 63,549 — treating every unadjudicated case in a growing backlog as though it had been denied. Our approval share of decisions for that same year is 71.0%. Neither is your odds, but if a page quotes a rate without saying what was divided by what, you cannot tell which of two calculations nearly thirty points apart you are reading.