text: #standardSQL
  # 16_10: Use of other Cache-Control directives (e.g., public, private, immutable)
  SELECT
    client,
    all_requests,
    total_using_control,
    directive,
    COUNT(0) AS occurrences,
    ROUND(COUNT(0) * 100 / total_using_control, 2) AS pct_of_control,
    ROUND(COUNT(0) * 100 / all_requests, 2) AS pct_all_requests
  FROM
    `httparchive.almanac.requests`,
    UNNEST(REGEXP_EXTRACT_ALL(LOWER(resp_cache_control), r'([a-z][^,\s="\']*)')) AS directive
  JOIN (
    SELECT
      client,
      COUNT(0) AS all_requests,
      COUNTIF(TRIM(resp_cache_control) != "") AS total_using_control
    FROM
      `httparchive.almanac.requests`
    WHERE
      date = '2019-07-01'
    GROUP BY
      client
  )
  USING (client)
  WHERE
    date = '2019-07-01'
  GROUP BY
    client,
    all_requests,
    total_using_control,
    directive
  ORDER BY
    occurrences DESC
  