condition mean min max ZT0-3 0.754457 0.493475 1.2588235 ZT4-7 0.7029195 0.7029195 0.7029195 ZT8-11 0.6736705000000001 0.6736705000000001 0.6736705000000001 ZT12-15 1.262249 0.987598 1.5369 ZT16-19 0.5284945 0.5284945 0.5284945 ZT20-23 0.633489 0.633489 0.633489