The NCHS mortality data is currently only available at the state level. It seems like it should be possible to aggregate it to the nation and HHS levels. (If it's not possible for some reason, we should document that so nobody tries to use state and aggregate themselves.) Having all our signals consistently available at HHS and nation when possible would make it easy to compare things.

There's no pressing need for this that I know of; I just noticed the inconsistency and think it'd be nice to fix.