prefix bsbm: <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/vocabulary/>
  prefix bsbm-inst: <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/>
  prefix xsd: <http://www.w3.org/2001/XMLSchema#>

  Select ?vendor (xsd:float(?belowAvg)/?offerCount As ?cheapExpensiveRatio)
  {
    { Select ?vendor (count(?offer) As ?belowAvg)
      {
        { ?product a %ProductType% .
          ?offer bsbm:product ?product .
          ?offer bsbm:vendor ?vendor .
          ?offer bsbm:price ?price .
          { Select ?product (avg(xsd:float(xsd:string(?price))) As ?avgPrice)
            {
              ?product a %ProductType% .
              ?offer bsbm:product ?product .
              ?offer bsbm:vendor ?vendor .
              ?offer bsbm:price ?price .
            }
            Group By ?product
          }
        } .
        FILTER (xsd:float(xsd:string(?price)) < ?avgPrice)
      }
      Group By ?vendor
    }
    { Select ?vendor (count(?offer) As ?offerCount)
      {
        ?product a %ProductType% .
        ?offer bsbm:product ?product .
        ?offer bsbm:vendor ?vendor .
      }
      Group By ?vendor
    }
  }
  Order by desc(xsd:float(?belowAvg)/?offerCount) ?vendor
  limit 10