condition mean min max ZT0-3 8.401297499999998 7.893549999999999 8.909044999999999 ZT4-7 4.15313 4.15313 4.15313 ZT8-11 2.341395 2.341395 2.341395 ZT12-15 0 0 0 ZT16-19 3.583665 3.583665 3.583665 ZT20-23 4.46568 4.46568 4.46568