WASHINGTON, DC - More than 1,000 inmates were added to the nation's prisons and jails each week from June 2004 to June 2005, according to a report issued Sunday by the U.S. Department of Justice.

The 56,428 new inmates -- including both convicts and those awaiting trial -- added to the system over the 12-month period account for a 2.6 percent rise in the U.S. prison and jail population, according to a synopsis of the Bureau of Justice Statistics report.

Two-thirds of the nearly 2.2 million total inmates were in state or federal prisons, and the rest were in local jails. Montana's state prison population saw the largest increase -- 7.9 percent -- closely followed by South Dakota -- up 7.8 percent. Both states have reported a spike in methamphetamine addiction -- particularly among female prisoners -- in their facilities.

In Montana, 85 percent of the state's female prisoners are incarcerated because of meth-related offenses, according to Rep. Denny Rehberg, a Republican member of the U.S. House Meth Caucus who has pushed for more funding of anti-meth media campaigns.

South Dakota's Department of Corrections Administration reported that, during a three-month period in 2005, 41 percent of its female prisoners were addicted to meth -- a rise of 11 percent from the previous year. The state's male prisoner population grew by 3 percent, according to the administration, which released the numbers in January.

"The data is clear: Drug use is driving up prison numbers throughout the region," the state's corrections secretary Tim Reisch said in the news release. "In South Dakota, we are directing our resources to address the issue head on."

Montana and South Dakota were among 10 states that saw more than 5 percent growth in their state prison systems, while 12 others -- including Vermont, Idaho and New York -- reported decreases.

The Sentencing Project, an advocacy group, reports that the U.S. incarceration rate in 2004 was the highest in the world, at 724 per 100,000 population. Second was Russia, at 532 per 100,000.

The Justice Department study's author told CNN that the comparison was not included in the report because it was not clear to U.S. authorities whether other countries compiled their information in the same way.