condition mean min max ZT0-3 1.4831466666666666 1.35419 1.6468 ZT4-7 1.4341949999999999 1.4341949999999999 1.4341949999999999 ZT8-11 1.0326095 1.0326095 1.0326095 ZT12-15 0.9937067500000001 0.9376180000000001 1.0497955 ZT16-19 0.9740035 0.9740035 0.9740035 ZT20-23 1.5594700000000001 1.5594700000000001 1.5594700000000001