condition mean min max ZT0-3 38.400000000000006 38.400000000000006 38.400000000000006 ZT4-7 7.1 7.1 7.1 ZT8-11 7.3 7.3 7.3 ZT12-15 39.45 39.45 39.45 ZT16-19 19.200000000000003 19.200000000000003 19.200000000000003 ZT20-23 45.9 45.9 45.9