Changes in, or additions to, the information contained in an employee's statement of employment and financial interests shall be reported in a supplementary statement as of June 30 each year. If no changes or additions occur, a negative report is required. Notwithstanding the filing of the annual report under this section, each employee shall at all times avoid acquiring a financial interest that could result, or taking an action that would result, in a violation of the conflicts of interest provisions of section 208 of title 18, United States Code, or the regulations in this part.