condition mean min max ZT0-3 8.002301 8.002301 8.002301 ZT4-7 9.361941 9.361941 9.361941 ZT8-11 8.0817315 8.0817315 8.0817315 ZT12-15 8.2741285 8.2741285 8.2741285 ZT16-19 8.9909555 8.9909555 8.9909555 ZT20-23 8.567795 8.567795 8.567795