condition mean min max ZT0-3 6.047945 5.488365 6.607525 ZT4-7 2.857235 2.857235 2.857235 ZT8-11 2.5755850000000002 2.5755850000000002 2.5755850000000002 ZT12-15 0 0 0 ZT16-19 4.241185 4.241185 4.241185 ZT20-23 4.811605 4.811605 4.811605