condition mean min max ZT0-3 14.982026977499999 14.581388624999999 15.38266533 ZT4-7 8.873394176249999 8.2200234515 9.526764901 ZT8-11 12.6934680525 10.834025815 14.55291029 ZT12-15 13.1888087675 12.68840208 13.689215455 ZT16-19 19.7951667375 18.204498865 21.38583461 ZT20-23 20.5964847325 18.74983882 22.443130644999997