condition mean min max ZT0-3 2.25909178525 1.705469417 2.8127141535 ZT4-7 9.883489061 8.752864152 11.01411397 ZT8-11 10.5417860795 9.9743986125 11.1091735465 ZT12-15 8.90029927825 8.811293636 8.9893049205 ZT16-19 15.2161117995 12.587237223999999 17.844986375 ZT20-23 18.01353764 16.973882675 19.053192605