condition mean min max ZT0-3 6.656255 6.052455 7.2600549999999995 ZT4-7 3.077955 3.077955 3.077955 ZT8-11 2.985425 2.985425 2.985425 ZT12-15 0 0 0 ZT16-19 4.652345 4.652345 4.652345 ZT20-23 5.27627 5.27627 5.27627