Table 7: Results with different tugboat deployment schemes.

Number of shipsResults with different tugboat deployment schemes
Scheme 11Scheme 22GAP1aScheme 33GAP2b

1028452833−0.42%2808−1.30%
1542054186−0.45%4159−1.09%
2054855421−1.17%5394−1.66%
2568576807−0.73%6785−1.05%
3083818325−0.67%8299−0.98%

Average//−0.69%/−1.22%

(value of 2 − value of 1)/value of 1 × 100%; b(value of 3 − value of 1)/value of 1 × 100%.