condition mean min max ZT0-3 0.088487356 0.0 0.176974712 ZT4-7 0.0 0.0 0.0 ZT8-11 0.0 0.0 0.0 ZT12-15 0.0 0.0 0.0 ZT16-19 0.0 0.0 0.0 ZT20-23 0.7932536423333334 0.0 1.5865072846666668