condition mean min max ZT0-3 2.77729 1.1920950000000001 3.827505 ZT4-7 2.266125 2.266125 2.266125 ZT8-11 2.8823749999999997 2.8823749999999997 2.8823749999999997 ZT12-15 2.9204575000000004 2.556925 3.28399 ZT16-19 4.409525 4.409525 4.409525 ZT20-23 5.65227 5.65227 5.65227