Marijuana is the most commonly used illicit drug in the United States. In 2013, an estimated 19.8 million individuals in the United States aged 12 or older (7.5% of this population) had used marijuana in the past month. While reported marijuana use is similar to that in 2012, it has generally increased since 2007 when 5.8% of individuals aged 12 or older were current users of marijuana. Mirroring this increase in use, marijuana availability in the United States has also increased. This growth has been linked to factors such as rising marijuana production in Mexico, and increasing marijuana cultivation in the United States led by criminal networks including Mexican drug trafficking organizations.