No matter how you put it, Nigerian OC is definitely on the rise. While their activities used to be limited to the smuggling of drugs, they now have set up individual cartels that are succesful and respected partners to their Colombian colleagues.
Another evolution is the following: 20 years ago the Nigerian groups weren't seen as very violent. While Nigerian fraudsters still aren't likely to be involved in violence, the drug traffickers and racketeers nowadays are known for being extraordinary violent.