condition mean min max ZT0-3 2.58433212175 2.5378566625 2.630807581 ZT4-7 2.25113305525 2.0013521505 2.50091396 ZT8-11 2.54554097675 2.3360732715 2.7550086819999997 ZT12-15 2.254279684 1.8963883714999998 2.6121709965 ZT16-19 4.3064805735 2.9902677495 5.622693397499999 ZT20-23 8.093839248750001 7.224611199 8.9630672985