condition mean min max ZT0-3 1.8815916666666668 1.31407 2.4168200000000004 ZT4-7 1.386975 1.386975 1.386975 ZT8-11 0.993352 0.993352 0.993352 ZT12-15 2.4919124999999998 2.215995 2.76783 ZT16-19 1.728315 1.728315 1.728315 ZT20-23 2.04267 2.04267 2.04267