They gave it as a defined term with a pdf copy of https://www.goodrx.com/drugs/medication-basics/which-is-the-... describing the ranges - I just neglected to include all of that detail in my comment :). Another example of why it's great to discuss with your doctor instead of advice from forum comments! Googling around, apparently these values are standardized for pharmacology in the US by the USP, other areas may have other standards.

Hope that helps!