condition mean min max ZT0-3 2.4000000000000004 2.4000000000000004 2.4000000000000004 ZT4-7 6.6 6.6 6.6 ZT8-11 4.85 4.85 4.85 ZT12-15 3.55 3.55 3.55 ZT16-19 6.65 6.65 6.65 ZT20-23 3.6 3.6 3.6