query: SELECT ?item ?partij ?positie WHERE {
    ?item p:P3602 ?electionstatement .
    ?electionstatement ps:P3602 wd:Q1457697 .
    OPTIONAL { ?electionstatement pq:P1268 ?partij }.
    OPTIONAL { ?electionstatement pq:P4243 ?positie }.
    } ORDER BY ?partij xsd:integer(?positie)