Hi, all, and thanks in advance for the help. I'm developing an application to track utility bills, and am experiencing some difficulty. Briefly, every month has me creating a document that reflects certain details of that month's utility bill. On the document, there are a few fields, including ones depicting the date the meter was read, the kilowatts used, a difference score (from baseline performance - expressed in kilowatts), and the date the document was created.

On the form/document, I'd also like to add a field that displays a cumulative sum of the difference scores. For example, we'll start in calendar year 2015. January's bill features a difference score of 25. Since it's the first month, its cumulative total is also 25. February features difference score of 30. It's cumulative total, therefore, is 55. March has a difference score of 10; the respective cumulative total is 65. And so on.

I'm having trouble finding an easy way to use formula language to code this field. Apologies if this is misdirected or unclear. I really do appreciate any advice you could offer. Thanks!