condition mean min max ZT0-3 6.5 6.5 6.5 ZT4-7 29.4 29.4 29.4 ZT8-11 3.3499999999999996 3.3499999999999996 3.3499999999999996 ZT12-15 4.2 4.2 4.2 ZT16-19 4.85 4.85 4.85 ZT20-23 5.2 5.2 5.2