condition mean min max ZT0-3 38.900000000000006 38.900000000000006 38.900000000000006 ZT4-7 8.8 8.8 8.8 ZT8-11 8.0 8.0 8.0 ZT12-15 41.5 41.5 41.5 ZT16-19 34.6 34.6 34.6 ZT20-23 56.75 56.75 56.75