condition mean min max ZT0-3 18.779075 17.75835 19.799799999999998 ZT4-7 15.680250000000001 15.680250000000001 15.680250000000001 ZT8-11 16.63725 16.63725 16.63725 ZT12-15 0 0 0 ZT16-19 18.6836 18.6836 18.6836 ZT20-23 18.84755 18.84755 18.84755