1
Every figure is rounded to a whole number. Shares are rounded to the nearest whole number.
Margins of error are always rounded up, so that they are never understated. (The national margin of error is only 0.5 to 0.6, depending on cycle, but is rounded up to 1 in each case.)
One seeming anomaly: A “C” is decided on the figures before rounding. So in five rows, the margin of error shown is equal to or larger than the share shown, but there is no “C”: before rounding, the margin of error was smaller than the share.