Gloss is measured in "gloss units" and not a percentage. The reference you list (Triboropaintcenter) is also incorrect. I reference the following (http://www.gloss-meters.com/GlossIntro2.html#4) for a better explanation of gloss, its measurement and units.
Common Names and Associated Gloss Values
Since we're missing a citation on the current table of common names/gloss values, I propose we use this list: http://www.rochelepainting.com.au/paint-sheen-level, which lists values very similar to the table already present: