The output consists on the number of instances that I have for each class before and after the sampler. Numbers are almost the same, I just get slightly differences. Am I wrongly counting  the instances?
Output:
Instances in class 0: 127
Instances in class 1: 131
Instances in class 2: 38
Instances in class 3: 154
Instances in class 4: 49
Instances in class 5: 130
Instances in class 6: 264
Instances in class 7: 44
Instances in class 8: 68
Instances in class 9: 242
Instances in class 10: 64
Instances in class 11: 40

Instances in class 0: 120
Instances in class 1: 132
Instances in class 2: 35
Instances in class 3: 174
Instances in class 4: 50
Instances in class 5: 133
Instances in class 6: 285
Instances in class 7: 29
Instances in class 8: 66
Instances in class 9: 213
Instances in class 10: 71
Instances in class 11: 43