condition mean min max ZT0-3 12.850000000000001 12.850000000000001 12.850000000000001 ZT4-7 1.7 1.7 1.7 ZT8-11 8.4 8.4 8.4 ZT12-15 1.55 1.55 1.55 ZT16-19 4.85 4.85 4.85 ZT20-23 4.05 4.05 4.05