condition mean min max ZT0-3 3.763455 3.447585 4.079325 ZT4-7 3.619795 3.619795 3.619795 ZT8-11 3.214385 3.214385 3.214385 ZT12-15 0 0 0 ZT16-19 6.102045 6.102045 6.102045 ZT20-23 5.433 5.433 5.433