EDIT: This is a screenshot of my flag history:
I think you could print screen your flag history from your profile and that's enough. I don't know if there is another way to do that.
Your flag history is private. You only (any maybe mods, not sure) can view it but other users can't.
I can't see yours; you can't see mine.
Thus, the best way to share your flag stats is via a screenshot or just copying the text.