Problems $1$ and $2$ are based on the following query:

SELECT EMP LNAME, EMP FNAME, EMP$\_$AREACODE, EMP$\_$SEX FROM EMPL$$YEE

WHERE EMP$\_$SEX $=\text{'}$F$\text{'}$ AND EMP AREACODE $=\text{'}615\text{'}$

ORDER BY EMP LNAME, EMP FNAME:

What is the likely data sparsity of the EMP$\_$SEX column?