condition mean min max ZT0-3 6.3292530285 5.51784906 7.140656997000001 ZT4-7 3.31754104525 3.2938608985 3.341221192 ZT8-11 3.5787950395 3.337003199 3.82058688 ZT12-15 9.566359922 7.497554024 11.63516582 ZT16-19 12.062170425 11.872500819999999 12.25184003 ZT20-23 13.2797104775 12.98708536 13.572335595