Thanks for you comments. Yes Diego, there is no specific order.. Actually my original data is the below one.. 20 trucks and 4 ports. I know this is harder than my previous data..
and here is the data:
n={{36.67, 23.33, 18.33, 12.33}, {20., 33.33, 30.83, 10.33}, {16.67,
60.83, 22.08, 16.13}, {26.67, 53.33, 24.33, 11.93}, {53.33, 43.33,
11.33, 14.33}, {60., 13.33, 14.58, 23.13}, {43.33, 33.33, 9.58,
16.13}, {36.67, 23.33, 27.08, 16.53}, {20., 28.33, 21.58,
24.73}, {33.33, 38.33, 29.08, 12.33}, {28.33, 68.33, 6.08,
11.13}, {45., 78.33, 30.33, 10.73}, {46.67, 38.33, 21.83,
15.73}, {53.33, 13.33, 13.33, 12.33}, {73.33, 23.33, 12.08,
18.13}, {13.33, 28.33, 19.58, 10.73}, {33.33, 33.33, 21.83,
21.93}, {26.67, 28.33, 27.58, 7.33}, {23.33, 18.33, 14.83,
6.93}, {33.33, 40.83, 30.08, 12.33}}