condition mean min max ZT0-3 17.87948240975 17.4262703095 18.33269451 ZT4-7 3.1438212542499997 2.3777474539999996 3.9098950544999997 ZT8-11 4.149563884 2.9715358600000004 5.327591908 ZT12-15 6.23802140025 5.980171576 6.4958712245 ZT16-19 5.0126134945 4.585022133 5.440204856 ZT20-23 10.30829777275 9.1537966705 11.462798875