condition mean min max ZT0-3 2.55 2.55 2.55 ZT4-7 1.4 1.4 1.4 ZT8-11 4.55 4.55 4.55 ZT12-15 4.45 4.45 4.45 ZT16-19 3.1500000000000004 3.1500000000000004 3.1500000000000004 ZT20-23 3.9 3.9 3.9