An all-time low 24% of underage filmgoers were able to purchase tickets to R-rated movies in 2012, according to an undercover shopper survey released Monday by the Federal Trade Commission.

The report, with also includes results from video game, music CD and DVD retailers, called the theatrical findings a “marked improvement in box office enforcement.” The FTC began the undercover program in 2000.

R-rated movie attendance among teens was at 33% in 2010.

“Our underage shopper survey shows continued progress in reducing sales,” said Charles Harwood, acting director of the FTC’s Bureau of Consumer Protection.  “But retailers can still strengthen their commitment to limit children’s access to products that are rated or labeled as potentially inappropriate for them.”

The Motion Picture Assn. of America chimed in about the report. CEO Chris Dodd said, “Since the rating system was created  44 years ago, the MPAA and our member companies have been dedicated to giving parents the tools and information about the content of our films.”

Also, the National Assn. of Theater Owners issued a statement in response to the findings, with CEO-prexy John Fithian saying, “We are proud of the significant improvement in ratings enforcement at America’s movie theaters and we renew our commitment to parents to continue to improve.”

Fithian additionally supported the voluntary ratings system: “We will continue to do our part in enforcing the voluntary ratings system that allows creators to create and parents to make informed decisions about their children’s entertainment.”

Also according to the survey, AMC, Regal and Marcus Theaters demonstrated the highest levels of enforcement. AMC turned away 95% of teen shoppers.

Music and homevid retailers saw lowered percentages of underage customers buying explicit material, at 30% and 47%, respectively. Vidgames, meanwhile, stayed flat with 2010.