condition mean min max ZT0-3 1.684635 1.684635 1.684635 ZT4-7 1.777225 1.777225 1.777225 ZT8-11 1.777115 1.777115 1.777115 ZT12-15 1.54229 1.54229 1.54229 ZT16-19 1.8000599999999998 1.8000599999999998 1.8000599999999998 ZT20-23 1.696545 1.696545 1.696545