condition mean min max ZT0-3 173.211219 173.211219 173.211219 ZT4-7 86.869421 86.869421 86.869421 ZT8-11 95.430398 95.430398 95.430398 ZT12-15 499.282299 499.282299 499.282299 ZT16-19 227.6575815 227.6575815 227.6575815 ZT20-23 665.0400475 665.0400475 665.0400475