Plastic bag use in Northern Ireland has fallen by almost 72% since a 5p levy was introduced last year, the Department of the Environment has said.
Environment Minister Mark H Durkan said the figure equated to a reduction of about 215 million bags.
It was the first set of official figures since charging for single-use carrier bags began in April 2013.
Mr Durkan said the £4.17m raised by the bag levy in the past year had been reinvested in environmental projects.
"I am delighted to announce that £2.5m of this year's levy receipts will be available to support community projects," he said.
"The community pays the levy and I will ensure that the community gets the benefit of the levy."
An estimated 300 million carrier bags were used in Northern Ireland in the year before the charge came in.
Retailers are required to charge at least 5p for each single-use carrier bag supplied new to customers and pay the net proceeds of the levy to the Department of the Environment.
The second phase of the bag levy will begin in January, when 5p will be added to the price of reusable bags that cost less than 20p.