Here's a link to a page at UESP with images of the three states.
https://en.uesp.net/wiki/Online:Grand_Master_Clothing_Station
The "Moderately Attuned" state came in at 30 sets, and I know the 77 set current maximum gives the "Fully Attuned". I did not notice when the "Lightly Attuned" change happened, but 5 sets was mentioned above, and I have no reason to doubt it. Unfortunately(?) you can add multiple sets at one time, so unless someone is deliberately adding them singly, the exact count is hard to determine.