[Tex/LaTex] How to draw a down arrow inside a table

tablestikz-arrowstikz-pgf

I want to draw a \downarrow (or any arrow) inside my table. The table is as shown in the one below:

And I want to to be more like this:

And this is the code I have:

$\rotatebox[origin=c]{90}{}% \left\Downarrow \begin{tabular}{lrr} \toprule {} & Aantal Zetels & Aantal Zetels \\ Strategie & Vrouwen & Mannen \\ \midrule a & 10 & 0\\ b & 4 & 6 \\ a & 8 & 2\\ b & 5 & 5 \\ a & 7 & 3 \\ b & 6 & 4 \\ \bottomrule \end{tabular} \right. \rotatebox[origin=c]{90}{}$


Can anyone help me out?

Since your question is tagged , I guess that a \tikzmark solution is fine. You have to run LaTeX twice for the arrow to show up in the correct position.

\documentclass{article}
\usepackage{booktabs,tikz}
\newcommand\tikzmark[1]{\tikz[remember picture] \node (#1) {};}
\begin{document}
\begin{tabular}{lrr}
\toprule
& Aantal Zetels & Aantal Zetels \\
Strategie & Vrouwen & Mannen \\
\midrule
a \tikzmark{a} & 10 & 0 \\
b & 4 & 6 \\
a & 8 & 2 \\
b & 5 & 5 \\
a & 7 & 3 \\
b \tikzmark{b} & 6 & 4 \\
\bottomrule
\end{tabular}
\tikz[remember picture,overlay] \draw[->] (a.center -| b.center) -- (b.center);
\end{document}