condition mean min max ZT0-3 1.528216 1.528216 1.528216 ZT4-7 4.937756 4.937756 4.937756 ZT8-11 2.17174 2.17174 2.17174 ZT12-15 1.670321 1.670321 1.670321 ZT16-19 4.642887 4.642887 4.642887 ZT20-23 2.644697 2.644697 2.644697