condition mean min max ZT0-3 0.03267995 0.032658 0.0327019 ZT4-7 0.425621 0.425621 0.425621 ZT8-11 0.55749 0.55749 0.55749 ZT12-15 0 0 0 ZT16-19 0.22558345 0.22558345 0.22558345 ZT20-23 0.3556375 0.3556375 0.3556375