condition mean min max ZT0-3 1.3531016666666666 1.198285 1.48034 ZT4-7 0.2449917 0.2449917 0.2449917 ZT8-11 0.570689 0.570689 0.570689 ZT12-15 0.568908 0.488213 0.649603 ZT16-19 0.9492895 0.9492895 0.9492895 ZT20-23 1.0263715 1.0263715 1.0263715