condition mean min max ZT0-3 4.206647499 0.533554678 7.87974032 ZT4-7 23.0866899325 19.443027985 26.73035188 ZT8-11 47.63987422 37.612048720000004 57.66769972 ZT12-15 72.70307049249999 64.23564179 81.17049919499999 ZT16-19 51.142253015 46.301865995 55.982640035 ZT20-23 35.68908683 30.06444887 41.31372479