Sparklines plot one point per day that had activity. If the period has no data at all, a flat line between the first and last day is drawn so the card is not empty. If only one day had data, a zero point for the previous day is added so a line can be drawn. When two or more days have data, only those days are plotted (days with no orders are skipped rather than filled with zeros, to avoid misleading dips). Hover over the line to see the daily values.