condition mean min max ZT0-3 6.90134 5.41222 8.63735 ZT4-7 3.4560649999999997 3.4560649999999997 3.4560649999999997 ZT8-11 3.754235 3.754235 3.754235 ZT12-15 4.76638 4.27417 5.25859 ZT16-19 4.625815 4.625815 4.625815 ZT20-23 7.265115 7.265115 7.265115