condition mean min max ZT0-3 0.036633 0.0 0.073266 ZT4-7 0.0 0.0 0.0 ZT8-11 0.0 0.0 0.0 ZT12-15 0.01709475 0.0 0.0341895 ZT16-19 0.028854966666666666 0.0 0.05770993333333333 ZT20-23 0 0 0