condition mean min max ZT0-3 212.238353 212.238353 212.238353 ZT4-7 238.160977 238.160977 238.160977 ZT8-11 167.03733 167.03733 167.03733 ZT12-15 204.446954 204.446954 204.446954 ZT16-19 70.393035 70.393035 70.393035 ZT20-23 67.8146605 67.8146605 67.8146605