condition mean min max ZT0-3 38.317325 33.47735 43.1573 ZT4-7 14.5288 14.5288 14.5288 ZT8-11 10.455275 10.455275 10.455275 ZT12-15 0 0 0 ZT16-19 25.0319 25.0319 25.0319 ZT20-23 32.692 32.692 32.692