NaN% is the percentage representation of the fraction sitemap.xml/undefined. In plain terms, trying to divide a real file name by something that doesn’t exist just ends up with an undefined result, which shows up as NaN% when you force it into a percentage format.
Even though the numbers don’t make sense, you can still talk about the idea. The “sitemap.xml” part usually refers to a website’s index of pages, while “undefined” means there’s nothing to divide by. That’s why the calculation can’t produce a real number.
Because the result is not a number, any rounding to two decimal places still leaves it as NaN%. It’s a placeholder that tells you the operation failed, not a meaningful percentage.
So, whenever you see sitemap.xml/undefined, just remember the answer will always be NaN% – a sign that the fraction can’t be evaluated in normal terms.
