condition mean min max ZT0-3 636.158285 636.158285 636.158285 ZT4-7 514.13003 514.13003 514.13003 ZT8-11 578.473677 578.473677 578.473677 ZT12-15 706.4097025000001 706.4097025000001 706.4097025000001 ZT16-19 927.9123065000001 927.9123065000001 927.9123065000001 ZT20-23 988.441083 988.441083 988.441083