condition mean min max ZT0-3 0.49429666666666666 0.21842850000000003 0.6617135 ZT4-7 0.5498295 0.5498295 0.5498295 ZT8-11 0.7259395 0.7259395 0.7259395 ZT12-15 0.79226625 0.746416 0.8381164999999999 ZT16-19 1.351945 1.351945 1.351945 ZT20-23 1.444455 1.444455 1.444455