Function trend_view 

pub fn trend_view(
    results: &DataQualityResults,
    metric: QualityMetric,
    bars: usize,
) -> TrendView<'_>

The Trends table for metric, bars wide: rows per segment first (the exact count, then on a sample the rows it drew), then every column the measure is above zero in somewhere, the one that moves most first. Each bar pools consecutive segments (their counts over their rows), so a daily grain over years reads as years, and a thin day’s sample does not make a bar alone. A segment the sample missed is a slot like any other, so a bar of them says so rather than vanish.