Mathematical language isn't perfectly understood by many people. People may well mistakenly use "regular average" when they really want the 'average per 30 days' but that doesn't change the meaning of those conditions, equally as people creating about "stationery automobiles" does not change the meaning of "stationery" or "stationary". https://financefeeds.com/singapores-mas-issues-landmark-guidance-on-copyright-wealth-verification/