Why is tlt-infer's label confidence threshold high above 1?

I don’t know what is this…?

This is tlt-infer labels(KITTI format).
Why is confidence threshold value above 1~
8.908, 8.738 , 8.135 , … ?
and why detected Big bbox with nothing object… It’s confidence threshold value is 8~49…? very high confidence

person 0.00 0 0.00 541.394 277.975 568.149 372.288 0.00 0.00 0.00 0.00 0.00 0.00 0.00 8.908
person 0.00 0 0.00 603.314 118.128 631.804 224.751 0.00 0.00 0.00 0.00 0.00 0.00 0.00 8.738
person 0.00 0 0.00 275.850 132.499 301.142 203.275 0.00 0.00 0.00 0.00 0.00 0.00 0.00 8.135
person 0.00 0 0.00 72.996 146.577 100.588 229.443 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.638
person 0.00 0 0.00 549.187 92.917 569.934 153.916 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.625
person 0.00 0 0.00 490.815 65.638 511.604 120.052 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.988
person 0.00 0 0.00 275.135 196.468 305.882 289.367 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.023
person 0.00 0 0.00 247.067 126.604 273.698 197.850 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.982
person 0.00 0 0.00 583.974 267.279 616.247 371.981 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.646
person 0.00 0 0.00 462.027 51.587 484.034 103.122 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.966
person 0.00 0 0.00 109.015 129.741 132.023 194.173 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2.856
person 0.00 0 0.00 100.377 0.000 187.369 210.873 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.876