Creating a table using tabulary
I am confronted with the problem that the lines of my table are too small, resulting in that the formulas touch the borders of the table. The code I used is given below.
\documentclass{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage{tabulary}
\usepackage{booktabs}
\usepackage{tabularx}
\begin{document}
\centering
\begin{tabulary}{18cm}{R|L L L}
\toprule
\hline
Mean squared error & MSE &= &$\frac{1}{n}\sum_{t=1}^{n}e_t^2$ \\
\hline
Root mean squared error & RMSE &= &$\sqrt{\frac{1}{n}\sum_{t=1}^{n}e_t^2}$ \\
\hline
Mean absolute error & MAE &= &$\frac{1}{n}\sum_{t=1}^{n}|e_t|$ \\
\hline
Mean absolute percentage error & MAPE &= &$\frac{100\%}{n}\sum_{t=1}^{n}\left |\frac{e_t}{y_t}\right|$\\
\hline\bottomrule
\end{tabulary}
\end{document}
How can I increase vertical space in my table so that it looks appropriate?