Question: When was the university which has Placidus Böcken as  Vice-Chancellor established? 
Sentence (from "University of Salzburg"): The University of Salzburg, also known as Paris Lodron University (German: "Paris-Lodron-Universität Salzburg" , PLUS) named after its founder, Prince-Archbishop , is a public university located in the Austrian city of Salzburg.
Relevant evidence: No