condition mean min max ZT0-3 2.16249367925 1.708201082 2.6167862765 ZT4-7 4.31664667325 2.761543229 5.8717501174999995 ZT8-11 8.118074463 6.5723985365 9.663750389499999 ZT12-15 7.929336835 7.635834501 8.222839169 ZT16-19 3.5281343334999997 3.3205235815 3.7357450855 ZT20-23 3.52200940575 3.366677503 3.6773413085