condition mean min max ZT0-3 2.4677866666666666 1.592485 3.09606 ZT4-7 2.512945 2.512945 2.512945 ZT8-11 2.52568 2.52568 2.52568 ZT12-15 2.8984449999999997 2.86468 2.93221 ZT16-19 2.830795 2.830795 2.830795 ZT20-23 3.0392200000000003 3.0392200000000003 3.0392200000000003