condition mean min max ZT0-3 1.6939405 1.5921850000000002 1.795696 ZT4-7 0.5652005 0.5652005 0.5652005 ZT8-11 11.73975 11.73975 11.73975 ZT12-15 0 0 0 ZT16-19 14.77844 14.77844 14.77844 ZT20-23 4.079305 4.079305 4.079305