condition mean min max ZT0-3 4.21499121875 4.054694405499999 4.375288032 ZT4-7 2.9990131015 2.6836219825 3.3144042205 ZT8-11 2.0804236982499997 1.9892689755 2.171578421 ZT12-15 8.31548987075 5.1675682965 11.463411445 ZT16-19 11.538333632499999 11.170533725 11.906133539999999 ZT20-23 14.845808190000001 14.422114610000001 15.269501770000002