condition mean min max ZT0-3 0.691454 0.691454 0.691454 ZT4-7 0.6493665 0.6493665 0.6493665 ZT8-11 0.2822205 0.2822205 0.2822205 ZT12-15 0.4940365 0.4940365 0.4940365 ZT16-19 1.2511299999999999 1.2511299999999999 1.2511299999999999 ZT20-23 0.702914 0.702914 0.702914