condition mean min max ZT0-3 3.1500000000000004 3.1500000000000004 3.1500000000000004 ZT4-7 22.4 22.4 22.4 ZT8-11 27.200000000000003 27.200000000000003 27.200000000000003 ZT12-15 34.0 34.0 34.0 ZT16-19 28.85 28.85 28.85 ZT20-23 21.6 21.6 21.6