I’m not related to any member of this family.
A person's DOB was only aske on the 1900 census.
all other census' state a person's age.
Here is why the age may differ -
everyone must age either 9 or 19 yr from one census to the next. Anything other than that indicates that they are lying or simply don;t know.
Each census has it's own calendar year which is stated at the top of the census page. If a person's birthday ocurred before the census yr stated; then that person will have aged 10 yrs. If the birthday ocurrs after the census yr starts, then that person has aged only 9 yrs.
Remember the "informant" is supplying the deceased's personal info. So sometimes it's guess work.