def _collect_cluster_stats(lane):
    """Retrieve total counts on cluster statistics.
    """
    stats = {"Clusters" : 0, "Clusters passed": 0}
    for tile in lane.find("Read").findall("Tile"):
        stats["Clusters"] += int(tile.find("clusterCountRaw").text)
        stats["Clusters passed"] += int(tile.find("clusterCountPF").text)
    return stats