When was the last referendum among Puerto Ricans declaring endorsement for the current relationship between that entity and the U.S.?

The last referendum among Puerto Ricans regarding their relationship with the United States took place on November 3, 2020. In this referendum, voters were asked whether they favored statehood, independence, or maintaining the current territorial status. The majority of voters chose statehood, although the turnout was relatively low, and the results were non-binding. This reflected ongoing debates about Puerto Rico's political status and relationship with the U.S.