In the administration of any trust which is a “private foundation,” as defined in Section 509 of the United States Internal Revenue Code, or which is a “charitable trust,” as defined in Section 4947(a)(1) of the United States Internal Revenue Code, there shall be distributed, for the purposes specified in the trust instrument, for each taxable year, amounts at least sufficient to avoid liability for the tax imposed by Section 4942(a) of the United States Internal Revenue Code.