A water sample analysis data is given below,

$$\begin{array}{|c|c|} \hline \textbf{Ion} & \textbf{Concentration, mg/L} & \textbf{Atomic Weight} \\ \hline Ca^{2+} & 60 & 40\\ \hline Mg^{2+} & 30 & 24.31 \\ \hline HCO_3^- & 400 & 61 \\ \hline \end{array}$$

The carbonate hardness (expressed as mg/L of $CaCO_3$, up to one decimal place), for the water sample, is ____