condition mean min max ZT0-3 0.42515833333333336 0.31820550000000003 0.4790655 ZT4-7 0.533973 0.533973 0.533973 ZT8-11 0.5529935 0.5529935 0.5529935 ZT12-15 4.3318224999999995 3.309285 5.35436 ZT16-19 2.720725 2.720725 2.720725 ZT20-23 1.354295 1.354295 1.354295