This may not have been your question, John, but just to make sure everyone saw this... On page 2 of the Final Assessment Instructions, it says:
If you provide appendices be sure they are in the same task section as the document that refers to it. Do not gather all the appendices at the end of the document.
I haven't planned any graphs in particular at this point, but in general I'd say that if it makes sense with the flow of the memo, go ahead and put it in the body. If it's more background or details, I'd make it an appendix.