condition mean min max ZT0-3 8.635635 8.38982 8.881450000000001 ZT4-7 16.45465 16.45465 16.45465 ZT8-11 3.70709 3.70709 3.70709 ZT12-15 0 0 0 ZT16-19 1.4621905 1.4621905 1.4621905 ZT20-23 7.070185 7.070185 7.070185