condition mean min max ZT0-3 17.25 17.25 17.25 ZT4-7 3.7 3.7 3.7 ZT8-11 6.8 6.8 6.8 ZT12-15 3.6500000000000004 3.6500000000000004 3.6500000000000004 ZT16-19 4.55 4.55 4.55 ZT20-23 4.9 4.9 4.9