Puerto Rico also held non-binding referendums in 1967, 1993 and 1998, with statehood never garnering a clear majority and independence never obtaining more than 5 percent of the vote.
In a poll this month, local newspaper El Nuevo Dia found that a very slim majority favored the current political status. On the second question, the preference for statehood topped sovereign free association. Few said they favor independence.
Associated Press reporter Ben Fox in San Juan, Puerto Rico contributed to this report.