condition mean min max ZT0-3 170.700829 170.700829 170.700829 ZT4-7 174.283212 174.283212 174.283212 ZT8-11 157.985445 157.985445 157.985445 ZT12-15 236.5645165 236.5645165 236.5645165 ZT16-19 274.49134549999997 274.49134549999997 274.49134549999997 ZT20-23 357.8642355 357.8642355 357.8642355