condition mean min max ZT0-3 2.23426977225 1.5086339455 2.959905599 ZT4-7 3.31542910725 1.9913542475 4.639503967 ZT8-11 7.761697115499999 6.770253668 8.753140562999999 ZT12-15 6.943899453 6.1265358615 7.7612630445 ZT16-19 5.3609765695 5.0860090295 5.6359441095000005 ZT20-23 7.513403144 6.610970828 8.41583546