condition mean min max ZT0-3 0.3602323333333333 0.2700675 0.445295 ZT4-7 0.401229 0.401229 0.401229 ZT8-11 0.3579485 0.3579485 0.3579485 ZT12-15 0.2077285 0.1668715 0.24858550000000001 ZT16-19 0.303191 0.303191 0.303191 ZT20-23 0.3633285 0.3633285 0.3633285