condition mean min max ZT0-3 47.400000000000006 47.400000000000006 47.400000000000006 ZT4-7 7.9 7.9 7.9 ZT8-11 22.950000000000003 22.950000000000003 22.950000000000003 ZT12-15 42.3 42.3 42.3 ZT16-19 11.100000000000001 11.100000000000001 11.100000000000001 ZT20-23 18.55 18.55 18.55