condition mean min max ZT0-3 11.279621 11.279621 11.279621 ZT4-7 10.177503 10.177503 10.177503 ZT8-11 9.964436 9.964436 9.964436 ZT12-15 9.1073315 9.1073315 9.1073315 ZT16-19 10.5158515 10.5158515 10.5158515 ZT20-23 10.2675395 10.2675395 10.2675395