condition mean min max ZT0-3 4.1032875735 3.6620151846666666 4.5445599623333335 ZT4-7 3.6911156165 3.4247172839999998 3.957513949 ZT8-11 3.5541724744999996 3.460197776 3.648147173 ZT12-15 3.782616775 3.673264595 3.891968955 ZT16-19 4.650416459833334 4.463972851666667 4.836860068 ZT20-23 4.9504466615 4.90819047 4.992702853