Probably a good choice to make up something to fill the bubble since otherwise half the people wouldn't read your end note and would complain that you left a speech bubble blank.
@Fim
Yeah, I could probably get away with just saying "tons". But I want to make sure people in the U.S. know it's not the US tons, which is 2000 pounds or 907 kg. On second thought, maybe I'm just paranoid. I have to worry about culture differences, US/metric units differences, and blank speech bubbles. >.>
@Fim@allenallenallen333 I suppose you could avoid the renaming and confusion by using "Tonne" instead of "Ton" since that's a specifically metric measurement. However, Megagrams is a synonym and sounds way more grandiose and sci-fi-chique so I'm glad you went that route anyway.