condition mean min max ZT0-3 10.829067 10.829067 10.829067 ZT4-7 8.3100195 8.3100195 8.3100195 ZT8-11 9.008682499999999 9.008682499999999 9.008682499999999 ZT12-15 9.2620235 9.2620235 9.2620235 ZT16-19 9.7262415 9.7262415 9.7262415 ZT20-23 10.130972499999999 10.130972499999999 10.130972499999999