condition mean min max ZT0-3 414.0655796 342.4715279 485.6596313 ZT4-7 246.503556675 243.16126144999998 249.8458519 ZT8-11 303.5194315 279.94312779999996 327.09573520000004 ZT12-15 260.98917695 240.45536385 281.52299005 ZT16-19 532.631098825 501.51946315 563.7427345000001 ZT20-23 777.064634725 687.3775796 866.75168985