condition mean min max ZT0-3 2.2815116666666664 2.2706999999999997 2.3019749999999997 ZT4-7 1.8880850000000002 1.8880850000000002 1.8880850000000002 ZT8-11 1.101245 1.101245 1.101245 ZT12-15 1.8466624999999999 1.822185 1.87114 ZT16-19 1.74662 1.74662 1.74662 ZT20-23 2.33636 2.33636 2.33636