condition mean min max ZT0-3 14.80559487 12.59086103 17.02032871 ZT4-7 20.666852625 17.905248125 23.428457125 ZT8-11 21.913558072500003 20.193321185000002 23.63379496 ZT12-15 26.5445594325 24.19376431 28.895354555 ZT16-19 47.08856685 44.05328915 50.12384455 ZT20-23 50.9638033 50.565498765 51.362107835