condition mean min max ZT0-3 57.400000000000006 57.400000000000006 57.400000000000006 ZT4-7 68.8 68.8 68.8 ZT8-11 76.85 76.85 76.85 ZT12-15 40.25 40.25 40.25 ZT16-19 65.25 65.25 65.25 ZT20-23 86.9 86.9 86.9