condition mean min max ZT0-3 26.978733333333334 20.7285 31.15325 ZT4-7 21.65985 21.65985 21.65985 ZT8-11 20.37845 20.37845 20.37845 ZT12-15 27.988349999999997 24.075899999999997 31.9008 ZT16-19 29.77865 29.77865 29.77865 ZT20-23 35.82465 35.82465 35.82465