condition mean min max ZT0-3 50.366955 50.366955 50.366955 ZT4-7 35.083393 35.083393 35.083393 ZT8-11 32.343202000000005 32.343202000000005 32.343202000000005 ZT12-15 31.0319845 31.0319845 31.0319845 ZT16-19 49.8095425 49.8095425 49.8095425 ZT20-23 64.723762 64.723762 64.723762