The data from a closed traverse survey PQRS (run in the clockwise direction) are given in the table
$$\begin{array}{|c|c|} \hline \text{Line} & \text{Included angle (in degrees)} \\ \hline PQ & 88 \\ \hline QR & 92 \\ \hline RS & 94 \\ \hline SP & 89 \\ \hline \end{array}$$
The closing error for the traverse PQRS (in degrees) is ______