condition mean min max ZT0-3 7.480143333333333 5.725325 9.122160000000001 ZT4-7 4.415505 4.415505 4.415505 ZT8-11 5.485614999999999 5.485614999999999 5.485614999999999 ZT12-15 8.690372499999999 8.195395 9.18535 ZT16-19 8.82592 8.82592 8.82592 ZT20-23 10.49198 10.49198 10.49198