condition mean min max ZT0-3 0.623295 0.0 1.18694 ZT4-7 0.0 0.0 0.0 ZT8-11 0.0 0.0 0.0 ZT12-15 0.0 0.0 0.0 ZT16-19 0.51514 0.51514 0.51514 ZT20-23 0.58136 0.58136 0.58136