docs: def get_cumulative_spend(key):
      """
      Get the sum of spending for this category up to and including the given
      month.
      """
      query = ('ROUND(SUM(total_ex_vat), 2) AS total '
               'FROM {table} '
               'WHERE date <= "{year}-{month:02}-01" '
               'AND lot="{lot}" '
               'AND customer_sector="{sector}" '
               'AND supplier_type="{sme_large}"'.format(
                   table=_RAW_SALES_TABLE,
                   year=key.year,
                   month=key.month,
                   lot=key.lot,
                   sector=key.sector,
                   sme_large=key.sme_large))
      logging.debug(query)
      result = scraperwiki.sqlite.select(query)
      logging.debug(result)
      value = result[0]['total']
      return float(result[0]['total']) if value is not None else 0.0