If you are blanking out the ID it would be great if you can leave the date of birth so we can see their real age.
I would advocate for year of birth or possibly year and month. Date of birth is quite revealing. For instance, Hungary has c. 91,000 live births per annum (source: Wikipedia), of which 50% are presumably female. 45,500 female births evenly distributed across 365 days means that if you know a female Hungarian's date of birth you've narrowed down her real identity to 1 of only 125 people.