condition mean min max ZT0-3 3.9115075000000004 3.582835 4.2401800000000005 ZT4-7 2.66702 2.66702 2.66702 ZT8-11 2.29695 2.29695 2.29695 ZT12-15 0 0 0 ZT16-19 3.018865 3.018865 3.018865 ZT20-23 3.640105 3.640105 3.640105