That is just foolish. You know better than that. They are only looking for an average of 10 bills per trailer. They know as well as everyone else that there will be loads that fall short of 10 bills per trailer as well as loads that far exceed 10 bills.
Where they are completely missing it is the bill count does not accomplish their true goal, but they don't want to come out and tell you how much revenue per trailer they really want. It is all about revenue per trailer and nothing else. For obvious reasons, the more revenue they can put on the trailer they happier everyone will end up in the long run, but they are ignoring several factors that impact that revenue per trailer by focusing on the wrong goal. Typical.