condition mean min max ZT0-3 2.5500000000000003 2.5500000000000003 2.5500000000000003 ZT4-7 7.2 7.2 7.2 ZT8-11 2.35 2.35 2.35 ZT12-15 3.2 3.2 3.2 ZT16-19 24.599999999999998 24.599999999999998 24.599999999999998 ZT20-23 7.1 7.1 7.1