condition mean min max ZT0-3 0.33687516666666667 0.2498465 0.44547950000000003 ZT4-7 0.4002185 0.4002185 0.4002185 ZT8-11 0.438229 0.438229 0.438229 ZT12-15 0.2399865 0.1912375 0.2887355 ZT16-19 0.3093625 0.3093625 0.3093625 ZT20-23 0.384269 0.384269 0.384269