On: 87% of the U.S. Population are uniquely identified...

[tlb]

But if you poll the database every day to see when age increases, you can get DOB.

[nkassis → tlb]

Well... if the records are released I don't think they should change. Someone record at 50 isn't the same as at 60. Unless these are live datasets.

[zeratul → nkassis]

Correct you would not be able to guess the date of birth - the date of visit is removed.