condition mean min max ZT0-3 1.9102664999999999 1.2156445 2.62566 ZT4-7 1.28846 1.28846 1.28846 ZT8-11 0.7558050000000001 0.7558050000000001 0.7558050000000001 ZT12-15 1.21784925 1.141935 1.2937635 ZT16-19 2.515615 2.515615 2.515615 ZT20-23 3.044165 3.044165 3.044165