condition mean min max ZT0-3 0.0217379 0.0 0.0434758 ZT4-7 0.0132635 0.0132635 0.0132635 ZT8-11 0.0 0.0 0.0 ZT12-15 0.0 0.0 0.0 ZT16-19 0.005696466666666667 0.0 0.011392933333333334 ZT20-23 0 0 0