condition mean min max ZT0-3 2.97675659025 2.449789526 3.5037236545 ZT4-7 2.95793623 2.63898176 3.2768907 ZT8-11 2.845677751 2.589860058 3.101495444 ZT12-15 2.53211654375 2.1773983465000004 2.886834741 ZT16-19 4.048197246 2.837940923 5.258453568999999 ZT20-23 8.247494654499999 7.9975486605 8.4974406485