condition mean min max ZT0-3 3.15 3.15 3.15 ZT4-7 4.8 4.8 4.8 ZT8-11 3.85 3.85 3.85 ZT12-15 6.8500000000000005 6.8500000000000005 6.8500000000000005 ZT16-19 8.25 8.25 8.25 ZT20-23 4.75 4.75 4.75