condition mean min max ZT0-3 394.114613 394.114613 394.114613 ZT4-7 276.7000795 276.7000795 276.7000795 ZT8-11 277.2073405 277.2073405 277.2073405 ZT12-15 331.56275500000004 331.56275500000004 331.56275500000004 ZT16-19 302.86737200000005 302.86737200000005 302.86737200000005 ZT20-23 320.62765049999996 320.62765049999996 320.62765049999996