condition mean min max ZT0-3 3.435763455 2.8458258450000002 4.025701065 ZT4-7 17.94612127925 8.809887268499999 27.08235529 ZT8-11 35.161982144999996 34.174541375 36.149422915 ZT12-15 7.333403629499999 3.7468408049999997 10.919966453999999 ZT16-19 3.43650760425 2.94561679 3.9273984185 ZT20-23 1.83001261875 1.677783443 1.9822417945