Build a chart with traceable numbers
Keep data, units, and interpretation together.
Prepare
Start with a source table, not a visual shape. Write down the measurement, unit, period, geography, and source URL for each value. Check whether series use the same definition before putting them on one axis.
Work through the decision
Choose a chart suited to the question. Bars compare categories; a sequence can show change over time. Label the scale clearly. If only two values matter, a simple comparison may communicate more accurately than a crowded chart.
Review the result
Read each displayed value against the source after editing. Check zeroes, decimal separators, percentages, and the distinction between percentage change and percentage points. Avoid narration that claims causation from a visual correlation alone.