condition mean min max ZT0-3 20.97671666666667 10.9559 28.39735 ZT4-7 8.802295 8.802295 8.802295 ZT8-11 4.10141 4.10141 4.10141 ZT12-15 6.10469 6.08005 6.1293299999999995 ZT16-19 10.231645 10.231645 10.231645 ZT20-23 22.9213 22.9213 22.9213