condition mean min max ZT0-3 6.667586666666667 4.0613 9.70157 ZT4-7 8.09245 8.09245 8.09245 ZT8-11 9.0185 9.0185 9.0185 ZT12-15 4.2228200000000005 1.56066 6.8849800000000005 ZT16-19 1.59383 1.59383 1.59383 ZT20-23 1.4460384999999998 1.4460384999999998 1.4460384999999998