Complex sentence: With 64% of the electorate turning out the referendum passed with a 66.83% margin in favor, 33.17% against, of ascension to the EU, which would take place on 1 May of the following year.
Split into simpler sentences: With 64% of the electorate turning out the referendum passed with a 66.83% margin in favor, 33.17% against. Accession to the EU took place on 1 May of the following year.