condition mean min max ZT0-3 3.904305 3.55506 4.25355 ZT4-7 3.82683 3.82683 3.82683 ZT8-11 3.9440749999999998 3.9440749999999998 3.9440749999999998 ZT12-15 0 0 0 ZT16-19 4.450115 4.450115 4.450115 ZT20-23 4.235745 4.235745 4.235745