• List of people with their copyright representatives (duplicates if they have more than one) https://w.wiki/CVx
• Percent of people with a copyright representative (any) : https://w.wiki/CVz
• Percent of people witha CISAC representative : https://w.wiki/CW3

https://w.wiki/CW9

select ?item ?itemLabel ?makerLabel ?representedLabel where
{

?item wdt:P276 wd:Q679527 .    #locatie Boymans van Beuningen
?item wdt:P170 ?maker .        #bepalen wie de maker is
#?maker wdt:P1875 wd:Q2377084 . #de maker is aangesloten bij Pictoright
?maker wdt:P1875 ?represented  #represented by any org
       {service wikibase:label {bd:serviceParam wikibase:language "nl"}}

} order by ?represented

I found 154 items that do not have a maker at all.
Obviously they will not be shown in the above query, and might influence the outcome of the calculated percentages

https://w.wiki/CWT
select ?item ?itemLabel ?makerLabel ?representedLabel where
{

?item wdt:P276 wd:Q679527 .    #locatie Boymans van Beuningen
OPTIONAL {?item wdt:P170 ?maker} .        #bepalen wie de maker is

{service wikibase:label {bd:serviceParam wikibase:language "nl"}}
FILTER (!bound(?maker))

}

Almost 8000 items have a maker that has no defined representation.
I think that is correct for most of them, but if we miss the representation on some of the makers, it will also influence the percentage you calculate. Looking critically at the outcome of the below query can therefor increase the quality of the data, and the quality of the final calculated percentage

https://w.wiki/CWU
select ?item ?itemLabel ?makerLabel ?representedLabel where
{

?item wdt:P276 wd:Q679527 . #locatie Boymans van Beuningen
?item wdt:P170 ?maker . #bepalen wie de maker is
#?maker wdt:P1875 wd:Q2377084 . #de maker is aangesloten bij Pictoright
OPTIONAL {?maker wdt:P1875 ?represented} #represented by any org

FILTER (!bound(?represented))
     {service wikibase:label {bd:serviceParam wikibase:language "nl"}}

} order by ?represented

If anyone has additional queries or remarks to this request, feel free to add!