condition mean min max ZT0-3 27.934675 26.717599999999997 29.15175 ZT4-7 29.7241 29.7241 29.7241 ZT8-11 33.4818 33.4818 33.4818 ZT12-15 0 0 0 ZT16-19 39.528800000000004 39.528800000000004 39.528800000000004 ZT20-23 30.057750000000002 30.057750000000002 30.057750000000002