condition mean min max ZT0-3 1298.477227 1298.477227 1298.477227 ZT4-7 1183.7861425 1183.7861425 1183.7861425 ZT8-11 1059.4874165 1059.4874165 1059.4874165 ZT12-15 1171.545744 1171.545744 1171.545744 ZT16-19 992.901173 992.901173 992.901173 ZT20-23 859.160296 859.160296 859.160296