| Type | Fitting coefficient | Correlation coefficient R2 | ||
| a | b | c | ||
| GFS-0.00 | 0.00006247 | 0.13784 | −0.32702 | 0.97332 |
| GFS-0.01 | 0.00007347 | 0.06584 | −0.68599 | 0.90497 |
| GFS-0.03 | 0.00000012 | 0.03555 | −0.39921 | 0.93008 |
| GFS-0.05 | 0.00009995 | 0.04656 | −0.4435 | 0.96235 |
| GFS-0.07 | −0.00007094 | 0.18157 | −0.94429 | 0.91006 |