condition mean min max ZT0-3 0.0 0.0 0.0 ZT4-7 0.016323306 0.0 0.032646612 ZT8-11 0.0101805275 0.0 0.020361055 ZT12-15 0.014915565833333333 0.0 0.029831131666666667 ZT16-19 0.0 0.0 0.0 ZT20-23 0.0212167075 0.02113727 0.021296145