condition mean min max ZT0-3 16.049637 16.049637 16.049637 ZT4-7 18.560494499999997 18.560494499999997 18.560494499999997 ZT8-11 19.014467 19.014467 19.014467 ZT12-15 20.6571 20.6571 20.6571 ZT16-19 19.938996000000003 19.938996000000003 19.938996000000003 ZT20-23 23.779906 23.779906 23.779906