condition mean min max ZT0-3 2.7410449999999997 2.59908 2.88301 ZT4-7 2.297635 2.297635 2.297635 ZT8-11 2.42604 2.42604 2.42604 ZT12-15 0 0 0 ZT16-19 8.82225 8.82225 8.82225 ZT20-23 7.38233 7.38233 7.38233