Table 3. Statistical table of samples with different research methods.
| Research method | Number of samples | Sample proportion (%) | I 2 |
| Parametric method | 95 | 40.77 | 98.6 |
| Non-parametric method | 62 | 26.61 | 91.9 |
| Allometric growth equation | 76 | 32.62 | 97.2 |
| Total | 233 | 100 |