condition mean min max ZT0-3 394.385903 394.385903 394.385903 ZT4-7 326.31133550000004 326.31133550000004 326.31133550000004 ZT8-11 308.8254975 308.8254975 308.8254975 ZT12-15 365.779535 365.779535 365.779535 ZT16-19 430.6752585 430.6752585 430.6752585 ZT20-23 510.02005199999996 510.02005199999996 510.02005199999996