condition mean min max ZT0-3 4.4531149999999995 1.62542 6.205819999999999 ZT4-7 1.106679 1.106679 1.106679 ZT8-11 1.41072 1.41072 1.41072 ZT12-15 3.3940824999999997 2.954865 3.8333 ZT16-19 5.481925 5.481925 5.481925 ZT20-23 7.55028 7.55028 7.55028