The graph tells me that further analysis would be purposeless. For most countries, which entered EU in 2004 the fifth year in the union was the time of global crisis. Would have they been better without EU? Well, this is a topic for a deeper analysis.
What: The graph shows 3-year moving averages of annual GDP per capita growth, with value at year 0 (entering the EU) subtracted from all the data series for visual purposes. The “average” is a simple average of all growths without the topmost and downmost values.
When: Years are different for each country depending on its date of joining the European Union.
Where: Countries joined the EU in 2004 and later.