condition mean min max ZT0-3 1.3529197695 0.622190797 2.083648742 ZT4-7 5.705077295 5.2177462734999995 6.1924083165 ZT8-11 10.378067151 10.113022576999999 10.643111725 ZT12-15 11.29323616725 10.6884990795 11.897973255 ZT16-19 10.99841621475 10.9722842595 11.02454817 ZT20-23 9.36098427475 9.137020738 9.584947811500001