High-Temp Resin Empty, but only 0.5L printed

According to my dashboard, I have only printed 0.5L with the high-temp resin. By my calculations, the tank currently has roughly 0.25L in it. But the resin canister is empty.

I have never emptied the tank and have not printed cupped things (which would capture excess resin in the print itself), and yet the resin canister is empty.

Where did the other 0.25L go?

Never mind. my estimate of the depth was wrong; it looked to be around 5mm deep, but I measured it as being closer to 8-9mm, which would put it around 450 mL, which is significantly closer to the error tolerance I was expecting for losses due to resin coating the final parts.