about (the train.json and the validaton.json)'s number question

[moonlight52137]

hello,thank you for your work.could you tell me why the train.json and the validaton.json in total have 112798(54919+57876) items less then the bounding_box_smthsmth_part1-4.json's items 180049 and why the train.json'number and the validaton.json'number approximate 1:1 ??? i think that is not conform to common sense