Price-to-Sales

The index price-to-sales ratio is computed as follows

$$//<![CDATA[ \begin{array}{l}\displaystyle Price~to~Sales=\frac{Index~market~capitalisation}{\sum_{i=1}^{n} (sales_{i})}\end{array} //]]>$$

where:
$//<![CDATA[ \begin{array}{l}sales_{i}\end{array} //]]>$ denotes the sales of company i