condition mean min max ZT0-3 48.45415 47.93245 48.975849999999994 ZT4-7 27.11925 27.11925 27.11925 ZT8-11 18.4976 18.4976 18.4976 ZT12-15 0 0 0 ZT16-19 28.939999999999998 28.939999999999998 28.939999999999998 ZT20-23 39.98695 39.98695 39.98695