Marine aquaculture production relative to coastline length

PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX FishStatUnpivot: <http://semantic.eea.europa.eu/project/CSI033/FishStatUnpivot.csv#>
PREFIX countrygroups: <http://dd.eionet.europa.eu/vocabulary/common/countrygroups/>
PREFIX countries: <http://dd.eionet.europa.eu/vocabulary/common/countries/>
PREFIX wri_coastline: <http://semantic.eea.europa.eu/project/CSI033/wri_coastline.tsv#>

select
?year
?country
?group
?wri_coastline
round((sum(coalesce(?FishStatUnpivot,0))/?wri_coastline)*100)/100.0 as ?obsValue
sum(coalesce(?FishStatUnpivot,0)) as ?FishStatUnpivot

{{
  SELECT DISTINCT
    ?year
    ?country
    ?iso2
    ?group
    ?FishStatUnpivot
    ?wri_coastline
  WHERE {
    _:FishStatUnpivot FishStatUnpivot:country ?country .
    _:FishStatUnpivot FishStatUnpivot:iso2 ?iso2 .
    _:FishStatUnpivot FishStatUnpivot:group ?group .
    _:FishStatUnpivot FishStatUnpivot:environment ?environment .
    _:FishStatUnpivot FishStatUnpivot:year ?year .
    _:FishStatUnpivot FishStatUnpivot:obsValue ?FishStatUnpivot .
    FILTER (?group IN ('PISCES', 'MOLLUSCA'))

    FILTER (?environment = 'Marine')
    FILTER (?year = 2015)
    OPTIONAL { ?member skos:notation ?iso2 }.
    OPTIONAL { ?member rdfs:label ?country } .

    _:wri_coastline wri_coastline:geo ?iso2 .
    _:wri_coastline wri_coastline:obsValue ?wri_coastline .
  }
}}
ORDER BY ?year ?group ?country ?environment