condition mean min max ZT0-3 5.066535 4.957125 5.1759450000000005 ZT4-7 3.60447 3.60447 3.60447 ZT8-11 2.93086 2.93086 2.93086 ZT12-15 0 0 0 ZT16-19 4.662765 4.662765 4.662765 ZT20-23 5.230645 5.230645 5.230645