>>zoobab+(OP)
In any database whose fields have at least 4 meaningful ranges, 16 fields give 4.000.000.000 possibilities. Now I am on my iphone. As long as ranges are meaningful (i.e. they do divide the group in somewhat even parts), the individuating possibilities are HUGE. And fields do have usually many more than 4 ranges.
Anonymizing datasets is a weasel term.
The database is secure or it is not. As any database is quite likely insecure, we are doomed.