请帮我以英文学术论文的风格改写降重以下段落意思保持不变请注意我不需要你对其进行扩充。段落如下：PoseTrack2021 further extend pose annotations of the PoseTrack2018 dataset especially for particular small personss and person in crowds including 177164

PoseTrack2021 expands the pose annotations of the PoseTrack2018 dataset by focusing on small individuals and individuals in crowded scenes. A total of 177,164 pose annotations are included in this update. Furthermore, the flag indicating joint visibility has been redefined in PoseTrack2021, enabling the utilization of occlusion information.