condition mean min max ZT0-3 67.733184 67.733184 67.733184 ZT4-7 50.529814 50.529814 50.529814 ZT8-11 35.462924 35.462924 35.462924 ZT12-15 26.0052765 26.0052765 26.0052765 ZT16-19 23.526577500000002 23.526577500000002 23.526577500000002 ZT20-23 21.332596 21.332596 21.332596