condition mean min max ZT0-3 3.13733 3.13733 3.13733 ZT4-7 2.954135 2.954135 2.954135 ZT8-11 2.02136 2.02136 2.02136 ZT12-15 2.43813 2.43813 2.43813 ZT16-19 3.1781949999999997 3.1781949999999997 3.1781949999999997 ZT20-23 3.28095 3.28095 3.28095