The marijuana industry in the U.S. is ramping up and the legalization movement for the plant seems to have reached a tipping point. Washington and Colorado have already legalized the drug in a small way and other states appear to be following. Views on the drug are also changing and even the President has declared marijuana less dangerous than other, legal, drugs.

With all of this momentum for the marijuana movement, the critics who declared the plant a gateway drug might expect to see the use of harder drugs also increasing. This is not the case, at least with cocaine.

A new study published on the Office of National Drug Control Policy website this week shows that cocaine use in the U.S. dropped by around 50% from 2006 to 2010. This while marijuana consumption increased by more than 30% during the same period. The report’s authors were not able to gather enough data to estimate methamphetamine use past 2008. Likewise, the more recent spike in heroin overdoses is not included in the report.

The report, compiled by RAND Corporation, also includes U.S. spending estimates for various illegal drugs. It estimates that Americans bought upwards of $100 billion worth of marijuana, cocaine, heroin, and methamphetamine yearly – around $1 trillion spent during the first decade of the 21st century.

“Having credible estimates of the number of heavy drug users and how much they spend is critical for evaluating policies, making decisions about treatment funding and understanding the drug revenues going to criminal organizations,” said Beau Kilmer, lead author of the report and co-director of the Drug Policy Research Center at RAND. “This work synthesizes information from many sources to present the best estimates to date for illicit drug consumption and spending in the United States.”