condition mean min max ZT0-3 17.281 17.281 17.281 ZT4-7 19.11225 19.11225 19.11225 ZT8-11 16.1263 16.1263 16.1263 ZT12-15 12.753 12.753 12.753 ZT16-19 20.879399999999997 20.879399999999997 20.879399999999997 ZT20-23 17.003899999999998 17.003899999999998 17.003899999999998