Blame for export_stats.json

{
 "predicates_union": 10370,
 "predicates_train": 10102,
 "predicates_val_only": 268,
 "train": {
  "images": 472344,
  "boxes_from_json": 2666088,
  "rels": 4282531,
  "fallback_box": 2764,
  "boxes_from_pack": 2764
 },
 "val": {
  "images": 24964,
  "boxes_from_json": 140778,
  "rels": 226203,
  "fallback_box": 134,
  "boxes_from_pack": 134
 },
 "clean_train_excluded": 8687
}