condition mean min max ZT0-3 1.241812 1.191535 1.292089 ZT4-7 1.419425 1.419425 1.419425 ZT8-11 0.783473 0.783473 0.783473 ZT12-15 0 0 0 ZT16-19 1.28126 1.28126 1.28126 ZT20-23 1.398635 1.398635 1.398635