condition mean min max ZT0-3 1.93056 1.93056 1.93056 ZT4-7 2.83658 2.83658 2.83658 ZT8-11 3.1764449999999997 3.1764449999999997 3.1764449999999997 ZT12-15 2.5754925 2.5754925 2.5754925 ZT16-19 4.31049 4.31049 4.31049 ZT20-23 2.29878 2.29878 2.29878