condition mean min max ZT0-3 7.397347840249999 7.318193389499999 7.476502291 ZT4-7 7.220144225249999 6.8769647769999995 7.563323673499999 ZT8-11 9.578657651250001 6.5259916285 12.631323674 ZT12-15 16.2707316125 13.8135629 18.727900325 ZT16-19 19.3613861225 19.21720922 19.505563025 ZT20-23 18.237353565 18.000200805 18.474506325