Consider a database that has the relation schema EMP (EmpId, EmpName, and DeptName). An instance of the schema EMP and a SQL query on it are given below:
$$\overset{\text{EMP}}{\begin{array}{|c|c|c|}\hline\\
\textbf{EmpId}& \textbf{EmpName}& \textbf{DeptName}\\\hline
1& \text{XYA}& \text{AA} \\ \hline
2& \text{XYB}& \text{AA} \\ \hline
3& \text{XYC}& \text{AA} \\\hline
4& \text{XYD}& \text{AA} \\\hline
5& \text{XYE}& \text{AB} \\\hline
6& \text{XYF}& \text{AB} \\\hline
7& \text{XYG}& \text{AB} \\\hline
8& \text{XYH}& \text{AC} \\\hline
9& \text{XYI}& \text{AC} \\\hline
10& \text{XYJ}& \text{AC} \\\hline 11&\text{XYK} & \text{AD} \\\hline 12 & \text{XYL}& \text{AD} \\\hline 13 & \text{XYM} & \text{AE}
\\\hline\end{array}}$$
SELECT AVG(EC.Num)
FROM EC
WHERE (DeptName, Num) IN
(SELECT DeptName, COUNT(EmpId) AS
EC(DeptName, Num)
FROM EMP
GROUP BY DeptName)
The output of executing the SQL query is _____________ .