condition mean min max ZT0-3 2.7072648929999996 1.1289912519999998 4.285538534 ZT4-7 2.16448772675 1.12279426 3.2061811935 ZT8-11 5.030136187249999 3.3932200769999996 6.6670522975 ZT12-15 20.2168694065 18.467050848 21.966687965 ZT16-19 15.2815016895 14.285971954 16.277031425 ZT20-23 12.534349995749999 12.07095236 12.9977476315