median based on distinct values in another column

Hello,

I have data that looks like this:

I want to calculate the median age of the individual employees. Simply taking the median of age column is not good, since it counts Employee 1 and 4's ages twice.

I need a measure that counts distinct values in the employee column, then takes their median age. (Employees with blank age shouldn't be calculated)

Any idea about a formula that could do this?

Thanks!