condition mean min max ZT0-3 1.7131156666666667 1.134082 2.15101 ZT4-7 1.1558175 1.1558175 1.1558175 ZT8-11 2.74739 2.74739 2.74739 ZT12-15 3.4752225 3.262265 3.68818 ZT16-19 2.990735 2.990735 2.990735 ZT20-23 4.14348 4.14348 4.14348