condition mean min max ZT0-3 2.65 2.65 2.65 ZT4-7 4.1 4.1 4.1 ZT8-11 11.85 11.85 11.85 ZT12-15 2.9000000000000004 2.9000000000000004 2.9000000000000004 ZT16-19 2.55 2.55 2.55 ZT20-23 3.55 3.55 3.55