Thank you, I wont run a scraper on your website. The way I have worked it out would not have a issue with a rounding but requires me to know the ingame stam for each ilvl.
Take 203 ilvl. This is not a data point it have but ingame its 112 stam.
To work this out I had to do a Cubic spline interpolation. Basically there is an exp that needs working out. I graphed it https://tools.timodenk.com/cubic-spline-interpolation.
So on my graph I enter the 112 stam for x, I then get 8.286810-1 or 0.82868. This allows me to work it out.
So for ilvl 85 its 7889 stam in the database and the exp is EXP(0.8929875) or 2.442415. Thus I get, 37.99999 in excel. 7889/85/EXP(0.8929875) = 37.99 or 38 stam as per the websites which is why the websites being wrong is a problem.
So for ilvl 203 and stam 112. Its 7889/85/0.82868=111.99 stam. 'So in the wow tool item db its 7889 for stam for an ilvl of 85. https://www.wowdb.com/items/184736-robe-of-the-march-warden?itemLevelOverride=85 The value for stam has to be correct for this to work.
This method sucks and will likely change for every stat. Once you have the exp table you can create the stam value for any ilvl. Just wondering what method you were using. I have just done all this so its not fully checked. It works on two cloth chest items. One ilvl 85 in the db and the other ilvl 203 ingame. Hopefully its useful.
On https://www.wowhead.com/item=180098/sinister-requiem-vestments?bonus=1517:6805 for 203 ilvl the stam is 111. Ingame its 112. By my method its 112 even with the website data being a part of my graph.
Note I completed the above after talking to you. Going to load up wow and use to ingame raid game to add values to the table I have and see if the above holds out.