condition mean min max ZT0-3 41.094225 39.3954 42.79305 ZT4-7 26.77395 26.77395 26.77395 ZT8-11 19.1574 19.1574 19.1574 ZT12-15 0 0 0 ZT16-19 19.09915 19.09915 19.09915 ZT20-23 29.13995 29.13995 29.13995