condition mean min max ZT0-3 10.4416675 8.798285 12.085049999999999 ZT4-7 8.324375 8.324375 8.324375 ZT8-11 13.72255 13.72255 13.72255 ZT12-15 0 0 0 ZT16-19 9.490105 9.490105 9.490105 ZT20-23 6.773695 6.773695 6.773695