1520
In 1991 the percentage of Comorians residing in cities and towns of more than 5,000 persons was about 30 percent , up from 25 percent in 1985 and 23 percent in 1980 .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None