condition mean min max ZT0-3 2.79921812275 0.7346637490000001 4.8637724965 ZT4-7 6.15269215175 5.403523968 6.9018603355 ZT8-11 3.89813867575 3.1695809825000003 4.626696368999999 ZT12-15 1.64154704575 1.5704586835 1.7126354080000001 ZT16-19 2.04733392875 1.7320382365 2.362629621 ZT20-23 4.2566509435 4.085173377 4.4281285100000005