condition mean min max ZT0-3 20.044816666666666 13.9234 25.88295 ZT4-7 5.544605 5.544605 5.544605 ZT8-11 14.661349999999999 14.661349999999999 14.661349999999999 ZT12-15 27.056849999999997 24.160899999999998 29.9528 ZT16-19 23.232799999999997 23.232799999999997 23.232799999999997 ZT20-23 26.025100000000002 26.025100000000002 26.025100000000002