As I understand it, that was that they were looking at the volume that was actually shipped. Over the course of a time period, again I would have to.... In paragraph 6.43 it says:
Department data shows that the weight of items subsidized under the Nutrition North Canada program in the 2012–13 fiscal year had increased by about 25 percent compared with the weight subsidized in the final year of the Food Mail Program.
It's simply a comparison of the weight of what was shipped under the two programs between the 2012-13 fiscal year of the nutrition north program and then the last year of the food mail program.