condition mean min max ZT0-3 2.4000000000000004 2.4000000000000004 2.4000000000000004 ZT4-7 3.2 3.2 3.2 ZT8-11 16.35 16.35 16.35 ZT12-15 4.9 4.9 4.9 ZT16-19 16.7 16.7 16.7 ZT20-23 1.9 1.9 1.9