The fraction sitemap.xml/undefined as a percentage is NaN%. This result tells you that the value cannot be expressed as a normal number.
The reason is simple: the denominator “undefined” has no numeric value, so any division by it does not produce a real number. In mathematics, such a division is considered undefined, which is why the percentage shows up as “NaN” (Not a Number).
In practical terms, a sitemap.xml file is used to list the pages of a website for search engines. Trying to calculate a ratio with an undefined term doesn’t give any useful information, so the result remains non‑numeric.
If you ever see NaN% in a report, it’s a sign that something in the calculation is missing or incorrect, and you’ll need to fix the input before a meaningful percentage can be shown.
