condition mean min max ZT0-3 12.492802 12.492802 12.492802 ZT4-7 21.3371095 21.3371095 21.3371095 ZT8-11 23.345694 23.345694 23.345694 ZT12-15 18.616397 18.616397 18.616397 ZT16-19 15.9227305 15.9227305 15.9227305 ZT20-23 13.4165855 13.4165855 13.4165855