D.C. Mun. Regs. tit. 9, r. 9-301
On or before July 15th of each year the Mayor shall submit to the Council of the District of Columbia (Council), in accordance with the provisions of the Act, a proposed real property tax rate for the tax year; Provided, that the Mayor may extend for up to thirty (30) days the period for submitting the tax rate.
At the time the Mayor submits to the Council the proposed tax rate under § 301.1, the Mayor shall also submit, in addition to other information required by the Act, the real property tax rate (rounded to the nearest penny) calculated to yield in the tax year the same amount of revenue (exclusive of the revenue attributable to new construction) as was raised by the tax at the rate applicable during the year preceding the tax year.
When the rounding of the tax rate in accordance with § 301.2 does not yield the same amount of revenue as was obtained from the previous year's levy, the tax rate shall be increased to the nearest penny which will yield at least the same amount of revenue.
D.C. Mun. Regs. tit. 9, r. 9-301