condition mean min max ZT0-3 2.209295 2.209295 2.209295 ZT4-7 1.1907055 1.1907055 1.1907055 ZT8-11 5.721435 5.721435 5.721435 ZT12-15 15.2303 15.2303 15.2303 ZT16-19 8.64035 8.64035 8.64035 ZT20-23 4.481885 4.481885 4.481885