condition mean min max ZT0-3 2.7685516666666667 2.035885 4.231025 ZT4-7 0.962395 0.962395 0.962395 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 0.53247 0.53247 0.53247