condition mean min max ZT0-3 22.933125 22.314 23.55225 ZT4-7 17.57385 17.57385 17.57385 ZT8-11 15.75455 15.75455 15.75455 ZT12-15 0 0 0 ZT16-19 19.8563 19.8563 19.8563 ZT20-23 21.68975 21.68975 21.68975