condition mean min max ZT0-3 41.7 41.7 41.7 ZT4-7 3.5 3.5 3.5 ZT8-11 7.95 7.95 7.95 ZT12-15 30.1 30.1 30.1 ZT16-19 6.449999999999999 6.449999999999999 6.449999999999999 ZT20-23 4.0 4.0 4.0