condition mean min max ZT0-3 250.013599 250.013599 250.013599 ZT4-7 370.9553045 370.9553045 370.9553045 ZT8-11 437.90200600000003 437.90200600000003 437.90200600000003 ZT12-15 480.84744149999995 480.84744149999995 480.84744149999995 ZT16-19 389.9064815 389.9064815 389.9064815 ZT20-23 396.2670375 396.2670375 396.2670375