I currently have a table in latex that looks like:
\begin{tabular}{c|ll}
\hline
Unit (i) & \multicolumn{2}{c}{The combinations} \\
i & $(-1,-1,-1,-1)$ & $(-1,-1,+1,+1)$ \\
\hline
1 & $Y_{1}(-1,-1,-1,-1)$ & $Y_{1}(-1,-1,+1,+1)$ \\
2 & $Y_{2}(-1,-1,-1,-1)$ & $Y_{2}(-1,-1,+1,+1)$ \\
3 & $Y_{3}(-1,-1,-1,-1)$ & $Y_{3}(-1,-1,+1,+1)$ \\
4 & $Y_{4}(-1,-1,-1,-1)$ & $Y_{4}(-1,-1,+1,+1)$ \\
5 & $Y_{5}(-1,-1,-1,-1)$ & $Y_{5}(-1,-1,+1,+1)$ \\
\dotfill & \dotfill & \dotfill \\
N & $Y_{N}(-1,-1,-1,-1)$ & $Y_{N}(-1,-1,+1,+1)$ \\
\hline
Average & $\bar{Y}(-1,-1,-1,-1)$ & $\bar{Y}(-1,-1,+1,+1)$ \\
\hline
\end{tabular}
You can see that the last row has the average "bar" symbol touching the line created by hline. Is there a way to create more space in the last row, or possible add more vertical space to the other rows, without defining new commands? Thanks!