This begins to hint at something I've been kind-of hoping to see since this all started to break: internet companies competing with one another over who can be the most transparent. If only that were to have time and opportunity to set, and become the norm...
Can't you just separately report the number of non-confidential-law-enforcement requests (as an exact number), and let the reader take the difference?
Pretty sure the NSA isn't that stupid to leave that loophole wide open.
Similarly Google probably isn't allowed to disclose the past 6 months even in aggregate since they already published specifics.
If NSA has nothing to hide about FISA requests, what are they afraid of? Works both ways eh?