condition mean min max ZT0-3 13.3 13.3 13.3 ZT4-7 9.0 9.0 9.0 ZT8-11 42.400000000000006 42.400000000000006 42.400000000000006 ZT12-15 27.900000000000002 27.900000000000002 27.900000000000002 ZT16-19 6.25 6.25 6.25 ZT20-23 18.200000000000003 18.200000000000003 18.200000000000003