13396
Although the number of drugs in shortage in the United States in any given year is very small , the number of prescription drug shortages in the country nearly tripled between 2005 and 2010 .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None