Spending on federal-level lobbying has seen a significant drop in the last year.

More than two-thirds of the top 100 lobbying organizations from 2012 spent less on their lobbying efforts during the third quarter of 2013 than they did a year ago, according to the Center for Public Integrity (CFPI), which looked at congressional disclosure reports and Center for Responsive Politics data.

“Such developments are indicative of a lobbying industry in decline after more than a decade of unbridled growth,” Dave Levinthal, a senior reporter at the CFPI, wrote in a recent article. “Reasons for the slide are numerous, from a gridlocked Congress that rarely passes marquee legislation, to corporate investment in other forms of political influence, such as advertising campaigns and donating to politically active nonprofit groups.”

Staples of the top 100 that saw a decline in spending on lobbying activity included the U.S. Chamber of Commerce, the National Association of Realtors, the American Hospital Association, and the American Petroleum Institute.

However, while overall spending is on track to decline for the third year in a row, groups in the healthcare, agriculture, and firearms industries have ramped up their lobbying efforts as the political spotlight has been focused on their issues, according to the data.

The Grocery Manufacturers Association, prompted by the continuing debate over the farm bill, reported spending $7.2 million during the third quarter—more than five times the amount they reported during the previous quarter. GMA had never cracked $2 million in a single quarter, CFPI reported.

Advocacy groups on both sides of the gun-rights debate upped their spending as well. The National Rifle Association, which has led the fight against gun-control laws, spent $820,000 during the third quarter, but it was outspent by the National Association for Gun Rights, an upstart organization that supports NRA’s position—NAGR spent more than $1 million. Meanwhile, New York City Mayor Michael Bloomberg’s Mayors Against Illegal Guns spent $500,000.

And as the rollout of the Affordable Care Act gained steam and the launch of HealthCare.gov approached, groups with healthcare interests increased spending. The American Medical Association spent $4.27 million, the American Chemistry Council hit $4.75 million, and the Biotechnology Industry Organization spent $2.02 million.

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