condition mean min max ZT0-3 2.85 2.85 2.85 ZT4-7 2.6 2.6 2.6 ZT8-11 21.5 21.5 21.5 ZT12-15 4.4 4.4 4.4 ZT16-19 3.45 3.45 3.45 ZT20-23 2.3499999999999996 2.3499999999999996 2.3499999999999996