When should I mark my fill-up record as Missed-FillUps and what is it for?
Missed-FillUps is a marker to provide hint to fuel efficiency calculation process so that it knows how to calculate. Missed-FillUps means there have been some fill-ups which you have missed entering them before the current record (and you will never do). This gives hint that the calculation formula to reset its statistics from that record and start over.