Amortization expense of intangible assets for the years ended December 31, 2022, 2023 and 2024 amounted to RMB6,039,895, RMB6,686,070 and RMB4,766,969 (USD653,072), respectively.

Due to strategic optimization of leased-and-operated restaurants closures for varying reasons in each year, the Group recognized impairment losses of RMB18,892,000, RMB16,027,000 and RMB39,072,000 (USD5,352,842) for the years ended December 31, 2022, 2023 and 2024, respectively, to Da Niang Trademark in restaurant business segment. The Group evaluated the fair value of Da Niang Trademark using the relief from royalty method with the assistance of a third-party valuer and based on the significant assumptions including royalty rate for the trademark, projected revenue and discount rate, which were classified as level 3 inputs under the fair value hierarchy that involve considerable management judgements. Accordingly, actual results may vary significantly from the Group estimates as they are forward-looking and include assumptions about economic and market conditions with uncertain future outcome.

The estimated aggregate amortization expense for each of the five succeeding years is as follows: