condition mean min max ZT0-3 0.0 0.0 0.0 ZT4-7 0.0 0.0 0.0 ZT8-11 0.0 0.0 0.0 ZT12-15 0.040469553 0.0 0.080939106 ZT16-19 0.0 0.0 0.0 ZT20-23 0.07075267916666667 0.0 0.14150535833333333