condition mean min max ZT0-3 8.522449319 7.191075341000001 9.853823297 ZT4-7 5.281855607000001 5.106191818 5.457519396 ZT8-11 5.321856282000001 4.9568061945 5.686906369500001 ZT12-15 8.214209764 6.5799058295 9.8485136985 ZT16-19 11.846459574999999 11.154152295 12.538766854999999 ZT20-23 17.1972445625 17.157093265 17.23739586