condition mean min max ZT0-3 3.35 3.35 3.35 ZT4-7 1.4 1.4 1.4 ZT8-11 3.5999999999999996 3.5999999999999996 3.5999999999999996 ZT12-15 6.3500000000000005 6.3500000000000005 6.3500000000000005 ZT16-19 4.3 4.3 4.3 ZT20-23 4.35 4.35 4.35