lass="o">.</span><span class="n">getSortedListOfItemFrequencies</span><span class="p">())</span>
        <span class="k">return</span> <span class="p">(</span><span class="n">matrixSize</span> <span class="o">-</span> <span class="nb">sum</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">getSortedListOfItemFrequencies</span><span class="p">()</span><span class="o">.</span><span class="n">values</span><span class="p">()))</span> <span class="o">/</span> <span c