condition mean min max ZT0-3 1.224446903 0.632845325 1.816048481 ZT4-7 2.5828207242500003 1.2343518805000002 3.9312895680000004 ZT8-11 4.65363969825 4.167943343999999 5.1393360525 ZT12-15 4.7156703042500006 4.1340921195 5.297248489 ZT16-19 2.43402496025 2.1664363405 2.70161358 ZT20-23 4.53761941475 3.934022531 5.1412162985