condition mean min max ZT0-3 4.447965 4.447965 4.447965 ZT4-7 4.14257 4.14257 4.14257 ZT8-11 3.1322650000000003 3.1322650000000003 3.1322650000000003 ZT12-15 4.658465 4.658465 4.658465 ZT16-19 5.409075 5.409075 5.409075 ZT20-23 5.38951 5.38951 5.38951