Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: (CNN) Coalition forces, including American military operatives, killed a senior ISIS leader when conducting an operation on the Iraqi-Syrian border Wednesday, officials said. Killed was Sami Jassim Mohammed Al-Jabouri, known by the nom de guerre Haji Hamad, said the Kurdistan Region Security Council. His reported death is the latest victory in the coalition's ongoing fight against the terrorist organization's financial staying power. Jabouri was responsible for ISIS operations regarding natural resources in Iraq and Syria. He and an aide were killed in the operation. The United States has not verified Jabouri was the man killed in the mission but verified he was a key figure in ISIS oil operations.Coalition forces kill top ISIS leader who oversaw its oil resourcesThe fight over oil is key to undercutting the terrorist organization 
 Question:During that time, the population living under _ rule has fallen from 9 million to 6 million.

ISIS