condition mean min max ZT0-3 1.06344465825 0.692074546 1.4348147705 ZT4-7 1.014842088 0.910401526 1.11928265 ZT8-11 1.273054978 1.1688979305 1.3772120255 ZT12-15 0.801958768 0.516808032 1.087109504 ZT16-19 0.52552116175 0.297627821 0.7534145025 ZT20-23 0.9707685937499999 0.866497307 1.0750398804999999