I used to be asked this question by my administrators as well...many years ago.  But technically is illegal to ask someone their racial status on an application so I just quit gathering the info.  You could have a form the applicant fills out at the interview or at orientation that asks them to voluntarily submit information that you're not supposed to ask on the app...such as birthdate, race, marital status, etc.

We have an optional section on the application where applicants can choose to answer or not these type issues. This information is often needed if your hospital applies for federal grants, etc. 

It is the same procedure that is done for applicants in human resources.  It is also used so that we can describe the "average volunteer."  We actually had a person who came within a few months of being the exact age of our average volunteer.  She also met the education level, marital status, years of volunteering, number of hours of service in a year, etc.