condition mean min max ZT0-3 241.287207 241.287207 241.287207 ZT4-7 139.22008 139.22008 139.22008 ZT8-11 158.4308065 158.4308065 158.4308065 ZT12-15 297.879862 297.879862 297.879862 ZT16-19 236.04494799999998 236.04494799999998 236.04494799999998 ZT20-23 297.589427 297.589427 297.589427