2337
In terms of size , the Limescongress has developed from about 20 participants and 11 papers in 1949 to about 300 participants presenting 200 papers in the year 2012 , when the 22nd conference was held in the city of Ruse in Bulgaria .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None