Handguns for sale at Centennial Gun Club in Centennial, Colorado on Wednesday, Nov. 2, 2016.

(Nathaniel Minor/CPR News)

Colorado is on pace to have its lowest number of gun sales in five years.

Gun sales have trended down since President Donald Trump took office — but the decline has accelerated. Gun sales haven't gone up for 12 straight months.

In April, the Colorado Bureau of Investigation reported more than 14,000 background check approvals for handgun or long gun sales.

In the first four months of 2019, there have been more than 112,000 such background check approvals. For all of 2018, that number is more than 340,000. And, between 2017 and 2018, background check approvals were down more than 5 percent.

CPR uses approved background checks from the Colorado Bureau of Investigation as a proxy for sales.

And CBI reports that background checks have fallen by 10 percent so far this year. That translates to 13,000 fewer guns sold.

Gun stores say customers are still coming down from the gun buying binge of the Obama years and they don't fear new gun control measures with Trump in office.

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Several high profile shootings in recent weeks — both in Colorado and elsewhere — have led some gun control advocates and politicians to call for stricter nationwide gun control. Policies on cross-state gun purchases are also unclear.

Colorado Sen. Michael Bennet on Sunday again called for the implementation of a universal background check system in the U.S. Opponents say the proposal infringes on their Second Amendment rights.

The U.S. House has passed a bill to implement the checks, but Bennet said its prospects in the Senate are not good because Senate leadership will not allow the bill to come up for a vote.

"After Columbine in Colorado, the people of this Western state voted to close the gun show loophole and the internet loophole," Bennet said Sunday on ABC's This Week. "That was 20 years ago ... and every single year about 2 or 3 percent of the people that try to buy a gun in Colorado are stopped."

CBI reports that in 2018, more than 6,000 failed their background check in the state, which is about 1.8 percent of people applying.

Colorado Public Radio's Ben Markus contributed to this report.