| BP | LSTM | GRU | Bi-LSTM |
a | 0.6958 | 0.7169 | 0.9145 | 0.9376 |
b | 3.0125 | 2.9956 | 0.7887 | 0.5723 |
R2 | 0.5286 | 0.7716 | 0.7813 | 0.8988 |