Title-Include total production and consumption in food report
Summary-In the food report for bankers (and dukes I think) include totals of both production and consumption
Details-Can be either added to the table or the sentence that says "In summary, your realm appears to have a surplus of about x bushels per day."
Benefits-Ease of calculations for planning for islands with seasons.
Possible Exploits-None, its info that can already be gathered, this just makes it easier.
Another plus for this is that it shouldn't be more than a few lines to code.