condition mean min max ZT0-3 19.3647 19.3647 19.3647 ZT4-7 19.8549 19.8549 19.8549 ZT8-11 21.7578 21.7578 21.7578 ZT12-15 17.275199999999998 17.275199999999998 17.275199999999998 ZT16-19 22.3935 22.3935 22.3935 ZT20-23 20.544 20.544 20.544