condition mean min max ZT0-3 0.06841736666666667 0.0390866 0.12451665 ZT4-7 0.0 0.0 0.0 ZT8-11 0.02014725 0.02014725 0.02014725 ZT12-15 0.031218875 0.02226885 0.0401689 ZT16-19 0.03750065 0.03750065 0.03750065 ZT20-23 0.0219427 0.0219427 0.0219427