condition mean min max ZT0-3 17.054101 17.054101 17.054101 ZT4-7 18.1731655 18.1731655 18.1731655 ZT8-11 20.998868 20.998868 20.998868 ZT12-15 63.596737 63.596737 63.596737 ZT16-19 20.977304 20.977304 20.977304 ZT20-23 29.022376 29.022376 29.022376