condition mean min max ZT0-3 5.25 5.25 5.25 ZT4-7 31.5 31.5 31.5 ZT8-11 3.5500000000000003 3.5500000000000003 3.5500000000000003 ZT12-15 4.2 4.2 4.2 ZT16-19 25.75 25.75 25.75 ZT20-23 26.450000000000003 26.450000000000003 26.450000000000003