condition mean min max ZT0-3 9.56485137875 9.291867857 9.837834900499999 ZT4-7 8.212975147749999 7.081130011999999 9.344820283499999 ZT8-11 12.47362704575 11.0245055465 13.922748545000001 ZT12-15 27.7445271825 23.66155665 31.827497715 ZT16-19 35.8358708 34.765047555 36.906694045 ZT20-23 33.99111139749999 33.004970064999995 34.97725273