condition mean min max ZT0-3 1.2057012065 0.952784314 1.4586180989999997 ZT4-7 1.5092894993333332 1.289735769 1.7288432296666667 ZT8-11 3.6415303254999998 2.107823394 5.175237257 ZT12-15 8.495037104833333 6.605053031 10.385021178666667 ZT16-19 9.189715376166667 9.156282057333334 9.223148695 ZT20-23 4.7488408145 3.7853323079999996 5.7123493210000005