condition mean min max ZT0-3 4.46477 4.46477 4.46477 ZT4-7 4.08329 4.08329 4.08329 ZT8-11 3.1694 3.1694 3.1694 ZT12-15 3.54284 3.54284 3.54284 ZT16-19 5.564075 5.564075 5.564075 ZT20-23 5.162599999999999 5.162599999999999 5.162599999999999