A garden was infested with bug X. The gardener carried out an experiment. He sprayed a similar amount of pesticide A on two similar potted plants in the garden with 100 bug X in each pot.
The table below shows the number of bug X that died in each week.
| Number of bugs that died | ||
| Pot 1 | Pot 2 | |
| Week 1 | 15 | 16 |
| Week 2 | 14 | 12 |
| Week 3 | 13 | 10 |
| Week 4 | 11 | 10 |
What can be concluded from this experiment?