condition mean min max ZT0-3 36.37455 36.37455 36.37455 ZT4-7 24.1629 24.1629 24.1629 ZT8-11 23.4912 23.4912 23.4912 ZT12-15 32.43265 32.43265 32.43265 ZT16-19 23.089399999999998 23.089399999999998 23.089399999999998 ZT20-23 31.851399999999998 31.851399999999998 31.851399999999998