condition mean min max ZT0-3 3.8404460485000005 3.1037326430000003 4.577159454 ZT4-7 4.2267886377499995 3.4872470819999997 4.966330193499999 ZT8-11 6.05284557025 4.276879878999999 7.8288112615 ZT12-15 8.091110081250001 8.075494547 8.1067256155 ZT16-19 4.978204213250001 4.551224247 5.4051841795 ZT20-23 7.47500667975 6.657431103 8.2925822565