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The researchers estimate that at least 20,000 individuals made ransomware payments over the past two years , at a confirmed cost of $ 16 million , although the actual payment total is likely far higher .
 individuals: victim; over the past two years: time; $ 16 million: price
Given event type and trigger, please tell me the arguments of all the listed option. Output format is "name1: role1; name2: role2". 
Event type: ransom 
  Option: victim, attacker, payment method, attack pattern, damage amount, tool, time, price, place 
Text: {0} 
Answer:
 individuals: victim; over the past two years: time; $ 16 million: price