condition mean min max ZT0-3 4.9 4.9 4.9 ZT4-7 3.6 3.6 3.6 ZT8-11 14.2 14.2 14.2 ZT12-15 2.9 2.9 2.9 ZT16-19 2.6500000000000004 2.6500000000000004 2.6500000000000004 ZT20-23 4.300000000000001 4.300000000000001 4.300000000000001