The given distribution shows the number of runs scored by some top batsmen of the world in one-day international cricket matches. Find the mode of the data. \begin{array}{|c|c|} \hline \text{Runs scored} & \text{Number of batsmen} \\ \hline 3000 - 4000 & 4 \\ 4000 - 5000 & 18 \\ 5000 - 6000 & 9 \\ 6000 - 7000 & 7 \\ 7000 - 8000 & 6 \\ 8000 - 9000 & 3 \\ 9000 - 10000 & 1 \\ 10000 - 11000 & 1 \\ \hline \end{array}