condition mean min max ZT0-3 9.6 9.6 9.6 ZT4-7 3.9 3.9 3.9 ZT8-11 30.15 30.15 30.15 ZT12-15 34.900000000000006 34.900000000000006 34.900000000000006 ZT16-19 17.400000000000002 17.400000000000002 17.400000000000002 ZT20-23 2.55 2.55 2.55