condition mean min max ZT0-3 8.431003666666667 1.554521 12.88625 ZT4-7 0.348701 0.348701 0.348701 ZT8-11 1.1007395 1.1007395 1.1007395 ZT12-15 2.13005 0.406065 3.854035 ZT16-19 4.54824 4.54824 4.54824 ZT20-23 6.245025 6.245025 6.245025