condition mean min max ZT0-3 5.436765 5.436765 5.436765 ZT4-7 3.34461 3.34461 3.34461 ZT8-11 3.90957 3.90957 3.90957 ZT12-15 4.31844 4.31844 4.31844 ZT16-19 5.506095 5.506095 5.506095 ZT20-23 5.247285 5.247285 5.247285