The third column indicates for how many instances at least one exact algorithm finished within one hour. The fifth column indicates for how many instances the 2-approx option of CYCLEKILLER finished within one hour. For the remaining instances, the 4-approx option finished within one hour, as can be seen from the seventh column. The average running time for the 2-approx and the 4-approx in seconds are reported respectively in the sixth and eighth column. The average approximation ratio (ninth column) is taken over all instances for which at least one exact method finished. The last column indicates the percentage of those instances for which CYCLEKILLER found an optimal solution.