condition mean min max ZT0-3 13.112703333333334 10.12551 18.0139 ZT4-7 25.0531 25.0531 25.0531 ZT8-11 25.588549999999998 25.588549999999998 25.588549999999998 ZT12-15 18.1417 17.8071 18.476300000000002 ZT16-19 21.41095 21.41095 21.41095 ZT20-23 15.79525 15.79525 15.79525