Assistance with trend

[Bearack]

Pardon my ignorance here, but I'm drawing a blank on this. What I'm trying to get from the data presented is a trend that shows our volume in 2012, on a linear decline from our 2011 volumes. This is to be used to substantiate reducing our revenue in our budgets, know that we WON'T have the volumes we started our in the beginning of the new fiscal year. Help!



Thanks in advance for any help and sorry for the simplicity of the question.