condition mean min max ZT0-3 25.941135 25.941135 25.941135 ZT4-7 33.970994 33.970994 33.970994 ZT8-11 29.199512499999997 29.199512499999997 29.199512499999997 ZT12-15 28.9568035 28.9568035 28.9568035 ZT16-19 27.859399500000002 27.859399500000002 27.859399500000002 ZT20-23 32.06715 32.06715 32.06715