condition mean min max ZT0-3 1.5636733333333335 1.1948500000000002 1.7701500000000001 ZT4-7 1.069255 1.069255 1.069255 ZT8-11 0.978631 0.978631 0.978631 ZT12-15 1.5096100000000001 1.15246 1.8667600000000002 ZT16-19 1.325475 1.325475 1.325475 ZT20-23 1.85954 1.85954 1.85954