condition mean min max ZT0-3 3.3499999999999996 3.3499999999999996 3.3499999999999996 ZT4-7 2.5 2.5 2.5 ZT8-11 21.55 21.55 21.55 ZT12-15 7.9 7.9 7.9 ZT16-19 20.1 20.1 20.1 ZT20-23 2.5999999999999996 2.5999999999999996 2.5999999999999996