Read this: An error sometimes made is the confusion of discussion regarding Greece’s Eurozone entry with the controversy regarding usage of derivatives’ deals with U.S. Banks by Greece and other Eurozone countries to artificially reduce their reported budget deficits. A currency swap arranged with Goldman Sachs allowed Greece to "hide" 2.8 billion Euros of debt, however, this affected deficit values after 2001 (when Greece had already been admitted into the Eurozone) and is not related to Greece’s Eurozone entry.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): Why aren't the deficit values affected by the currency swap with Goldman Sachs relevant to Greece's Eurozone entry?
affected deficit values after 2001