Ecologists in Oregon studied the rate of decomposition of wood blocks placed in mesh bags on the forest floor. Wood blocks of equal initial mass were placed in bags of two different mesh sizes: fine mesh and coarse mesh. At intervals of six weeks, some of the bags were retrieved and the dry mass of the remaining wood was measured as a percentage of its original mass. The trial was continued for 24 weeks.
The data they collected are shown in the table below:
| Weeks | Dry mass of wood remaining (% of original mass) - Fine mesh | Dry mass of wood remaining (% of original mass) - Coarse mesh |
|---|---|---|
| 0 | 100 | 100 |
| 6 | 94 | 90 |
| 12 | 86 | 78 |
| 18 | 80 | 68 |
| 24 | 75 | 60 |
Calculate the percentage decrease in the dry mass of the wood in the coarse mesh bag by week 24.
