Ecology students investigated the population of woodlice (Oniscus asellus) in a deciduous woodland clearing over a period of 12 weeks.
To do this, they set up five pitfall trap stations, each consisting of a pitfall trap with a diameter of 10 cm. Every three weeks, they emptied the traps, recorded the number of woodlice caught at each station, and immediately released them back into the clearing.
Table 1 shows their results.
Table 1: Number of woodlice caught at each trap station
| Trap station | 0 weeks | 3 weeks | 6 weeks | 9 weeks | 12 weeks |
|---|---|---|---|---|---|
| 1 | 34 | 28 | 21 | 14 | 8 |
| 2 | 29 | 24 | YYY | 11 | 6 |
| 3 | 41 | 35 | 26 | 18 | 9 |
| 4 | 27 | 22 | 18 | 12 | 5 |
| 5 | 39 | 31 | 25 | 15 | 7 |
| Totals | 170 | 140 | 110 | 70 | 35 |
Value Y Y\,Y is the number of woodlice caught in trap station 2 at 6 weeks. Calculate the value of YYY.
Calculate the percentage decrease in the total number of woodlice caught at 12 weeks compared with 3 weeks.