The table gives the number of hazardous waste sites for selected states. Find the mode.
$$\begin{array}{l|c}\hline \text { State } & \text { Number of Sites } \\\hline \text { Florida } & 51 \\\hline \text { New Jersey } & 112 \\\hline \text { Michigan } & 67 \\\hline \text { Wisconsin } & 39 \\\hline \text { California } & 96 \\\hline \text { Pennsylvania } & 94 \\\hline \text { Illinois } & 39 \\\hline \text { New York } & 90 \\\hline\end{array}$$