public double weightedAverageArchivedSize() {
      return totalWeight == 0 ? archivedBytes.getAverage() : (weightedArchivedBytesSum * 1d / totalWeight);
    }
Returns average gzipped tile size in this aggregation, weighted by the {@link TileWeights} instance provided.
<p>
When multiple zoom-levels are combined, the weighted average respects the weight-per-zoom-level from
{@link TileWeights} so that low zoom tiles are not overweighted when analyzing a small extract.
planetiler-core/src/main/java/com/onthegomap/planetiler/util/TilesetSummaryStatistics.java