I want to know the answer to the following question:
When was Diaz Jr. elected?
All the background I'm provided with is that "His successor, Democratic New York State Assembly member Rubén Díaz, Jr., who won a special election on April 21, 2009 by a vote of 86.3% (29,420) on the "Bronx Unity" line to 13.3% (4,646) for the Republican district leader Anthony Ribustello on the "People First" line, became Borough President on May 1.". Is that enough to answer the question?
Answer: yes