condition mean min max ZT0-3 39.80215 39.80215 39.80215 ZT4-7 27.237000000000002 27.237000000000002 27.237000000000002 ZT8-11 26.7511 26.7511 26.7511 ZT12-15 27.678649999999998 27.678649999999998 27.678649999999998 ZT16-19 32.981700000000004 32.981700000000004 32.981700000000004 ZT20-23 34.0844 34.0844 34.0844