I want to know the answer to the following question:
When did Boko Haram become active in Nigeria?
All the background I'm provided with is that "At the same time, neighbouring countries, Benin, Chad, Cameroon and Niger joined Nigeria in a united effort to combat Boko Haram in the aftermath of a world media highlighted kidnapping of 276 schoolgirls and the spread of Boko Haram attacks to these countries.". Is that enough to answer the question?
Answer: no