condition mean min max ZT0-3 2.5246689399999998 2.434284774 2.615053106 ZT4-7 2.53853122875 2.144687524 2.9323749335 ZT8-11 3.536206269 2.8415259125 4.2308866255 ZT12-15 3.07777122875 2.883530288 3.2720121695 ZT16-19 3.7950408687499997 3.2068114439999995 4.3832702935 ZT20-23 4.682721461750001 4.6705300565000005 4.694912867