condition mean min max ZT0-3 76.002922 76.002922 76.002922 ZT4-7 141.685585 141.685585 141.685585 ZT8-11 227.19919399999998 227.19919399999998 227.19919399999998 ZT12-15 203.4150345 203.4150345 203.4150345 ZT16-19 142.156941 142.156941 142.156941 ZT20-23 86.38666 86.38666 86.38666