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The difference between the richest and poorest regions ( 281 NUTS-2 regions of the single market ) ranged , in 2017 , from 31 % ( Severozapaden , Bulgaria ) of the EU28 average ( € 30,000 ) to 253 % ( Luxembourg ) , or from € 4,600 to € 92,600 .
 Severozapaden, Bulgaria, Luxembourg
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Severozapaden, Bulgaria, Luxembourg